CN110899818B

CN110899818B - Pipe cutting device

Info

Publication number: CN110899818B
Application number: CN201911113067.5A
Authority: CN
Inventors: 陈惠玉; 羊贞
Original assignee: Yiwu Dingsha Knitting Co Ltd
Current assignee: Zhejiang Jinguo Intellectual Property Co ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-11-03
Anticipated expiration: 2039-11-14
Also published as: CN110899818A

Abstract

The invention relates to the technical field of machining, in particular to a pipe cutting device which can replace a manual handheld cutting tool to cut off a pipe, so that the section is smoother, secondary cutting caused by the fact that a buyer cannot install the pipe is avoided, the device is quicker to cut off, the working efficiency is high, and the practicability is improved; the rotary table comprises a workbench, supporting legs, a stiffening beam, a convex block, a screw rod, a gear, a baffle, double gears, a hinge, a rotary disk, a support, sliding supporting legs, pipe holes, a fixed support, a sliding fixing device, a cylinder, a piston, a motor, a transmission rod and a blade, wherein the top end of the fixed support is parallel and level to the top end of the support, the top end of the cylinder is connected with the bottom end of the sliding fixing device, the cylinder is connected with an air pump, the bottom end of the cylinder is connected with the top end of the piston in a sliding manner, the top end of the piston can slide up and down at the bottom end of the cylinder, the left end of the piston is connected with the.

Description

Pipe cutting device

Technical Field

The invention relates to the technical field of machining, in particular to a pipe cutting device.

Background

The pipe is a necessary material for building engineering, and the pipe is a material for manufacturing pipe fittings. Different pipes are used for different pipe fittings, and the quality of the pipes directly determines the quality of the pipe fittings. The multipurpose pipe materials in building engineering, power plants, chemical plants and the like have an execution standard GB/T53 rotating disc; for high-pressure boilers: there is an execution standard GB/T8 cylinder 3; seamless steel pipe for transporting fluid: there is a double gear 7 of the execution standard GB 3; seamless steel pipe for low pressure boiler: has an execution standard GB/T9948; seamless steel pipe for petroleum cracking: an execution standard GB/T fixed support 976 is provided; stainless steel seamless steel pipe for fluid transportation, common materials are alloy CrMo, sliding support leg Cr1MoV) carbon steel #, blade #, 45#) stainless steel and 3 cylinders). Some needs cut off tubular product when selling tubular product, and conventional operation is that the person of selling goods directly utilizes handheld saw to cut off tubular product, and the tubular product that this kind of cutting off mode was cut out probably leads to the incision not neat, leads to buyer to dock uneven phenomenon occasionally when using, and buyer still need carry out the secondary to tubular product and repaiies, and the practicality is not high.

Disclosure of Invention

In order to solve the technical problems, the invention provides a pipe cutting device which can replace a manual handheld cutting tool to cut off a pipe, so that the section is smoother, secondary cutting caused by the fact that a buyer cannot mount the pipe is avoided, the device is quick to cut off, the working efficiency is high, and the practicability is improved.

The invention relates to a pipe cutting device, which comprises a workbench, supporting legs, reinforcing beams, convex blocks, lead screws, gears, baffles, double gears, hinges, a rotary disk, a bracket, sliding supporting legs, pipe holes, fixed supports, a sliding fixing device, a cylinder, a piston, a motor, a transmission rod and blades, wherein the four corners of the bottom end of the workbench are respectively provided with the supporting legs, the top ends of the supporting legs are connected with the bottom end of the workbench, the reinforcing beams are arranged between the two groups of supporting legs, the two ends of the reinforcing beams are respectively connected with the inner sides of the supporting legs, the front end and the rear end of the workbench are respectively provided with two groups of convex blocks, the inner sides of the convex blocks are connected with the outer side of the workbench, the lead screws are arranged between the two groups of convex blocks, the two ends of the lead screws are respectively rotatably connected with the inner sides of the convex blocks, the gears are sleeved on, two groups of gears are respectively connected with the double gears through hinges, a transmission shaft at the right end of the double gears passes through a baffle plate and is connected with the left end of a rotary plate, the right end of the rotary plate is provided with a rotary handle, the rotary handle can drive the double gears to rotate, two groups of lead screws are driven to synchronously rotate through the hinges, two sides of the bottom end of a support are respectively provided with a sliding support leg, the top end of the sliding support leg is connected with the bottom end of the support, the bottom of the sliding support leg is provided with a threaded hole, the threaded hole at the bottom of the sliding support leg is matched and connected with the lead screw, the sliding support leg can slide left and right on the lead screw, the top end of the support is provided with a pipe hole, a fixed support is positioned at the left side of the support, the bottom end of the fixed support is connected with, the left end of the piston is connected with the right end of the motor, the motor is connected with the power supply, the output end of the right part of the motor is connected with the transmission rod, and the right end of the transmission rod penetrates through the piston to be connected with the left end of the blade.

The pipe cutting device also comprises an extension plate, a rotating bracket and a rotating support, wherein two parallel sliding plates are arranged at the bottom end of the workbench, the top end of each sliding plate is connected with the bottom end of the workbench, the two ends of the extension plate are respectively connected with the inner sides of the sliding plates in a sliding manner, the extension plate can slide left and right on the sliding plates, an upper groove is arranged at the top end of the extension plate, the rotating bracket is positioned in the upper groove, the left end of the rotating bracket is rotatably connected with the left part of the upper groove, when the rotating bracket is erected, the top end of the rotating bracket is flush with the top end of the pipe hole, when the rotating bracket is placed flat, the top end of the rotating bracket is lower than the top end of the extension plate, the bottom end of the extension plate is provided with two groups of grooves, the rotating support is positioned in the groove at the bottom end of the extension plate, the left end of the rotating support is rotatably connected with the left end of the groove, the bottom end of the extension plate is provided with a locking, when the rotary support is positioned in the groove, the rotary support cannot fall out of the groove through locking of the locking device.

The pipe cutting device further comprises a reinforcing rod, the reinforcing rod is located between the two groups of convex blocks and located on the upper side of the rotary support, two ends of the reinforcing rod are respectively connected with the inner sides of the convex blocks, through holes are formed in the upper portions of the sliding support legs, the through holes in the upper portions of the sliding support legs are concentrically connected with the reinforcing rod, and the sliding support legs can slide left and right on the reinforcing rod.

According to the pipe cutting device, the limiting piece is arranged at the right part of the reinforcing rod and sleeved on the reinforcing rod.

According to the pipe cutting device, the right end of the piston is provided with the protective cover, the left end of the protective cover is connected with the right end of the piston, part of the blades are positioned in the protective cover, and the blades are not in contact with the protective cover.

The pipe cutting device further comprises a screw and a cushion block, wherein the bottom end of each group of supporting legs is provided with a threaded hole, the top end of the screw is connected with the threaded hole at the bottom end of the supporting leg in a matched mode, the bottom end of the screw is rotatably connected with the top end of the cushion block, the bottom end of the cushion block is in contact with the ground, and the height of the supporting leg can be adjusted by rotating the screw.

According to the pipe cutting device, the cushion block is set to be the shock pad.

According to the pipe cutting device, the reinforcing rod is provided with the dial, and the bottom end of the dial is connected with the top end of the reinforcing rod.

Compared with the prior art, the invention has the beneficial effects that: an operator measures the length of a pipe to be cut, then holds a rotary handle to rotate a rotary disk, drives two groups of lead screws to synchronously rotate through a double gear, adjusts a support to a proper position, then places the pipe on the top end of the support, the bottom end of the pipe is respectively contacted with the support and the top end of a fixed support, then adjusts a blade to the top end of the pipe through a sliding fixing device, then starts a cylinder, presses a piston down until the bottom end of the blade is just contacted with the top end of the pipe, then energizes a motor, outputs power to the right end of the motor, drives the blade to rotate at a high speed through a transmission rod, cuts off the pipe, then controls the piston to ascend through the cylinder, closes the motor, stops rotating the blade, takes off the cut pipe, and can replace a manual handheld cutting tool to cut off the pipe through the device, so that the section is smoother, and secondary cutting caused by the, moreover, the device is fast in cutting off, high in working efficiency and high in practicability.

Drawings

FIG. 1 is a schematic front view of the present invention;

FIG. 2 is a schematic top view of the present invention;

FIG. 3 is a schematic view of the cutting apparatus of the present invention;

FIG. 4 is a schematic structural view of the transmission of the present invention;

FIG. 5 is a schematic top view of the support device of the present invention;

FIG. 6 is a schematic bottom view of the support device of the present invention;

FIG. 7 is a front view of the support device of the present invention;

FIG. 8 is a schematic view of the construction of the support device bracket of the present invention;

in the drawings, the reference numbers: 1. a work table; 2. supporting legs; 3. a reinforcing beam; 4. a bump; 5. a lead screw; 6. a gear; 7. a baffle plate; 8. a double gear; 9. a hinge; 10. rotating the disc; 11. a support; 12. a sliding leg; 13. a tube hole; 14. fixing and supporting; 15. a sliding fixture; 16. a cylinder; 17. a piston; 18. a motor; 19. a transmission rod; 20. a blade; 21. a slide plate; 22. an extension plate; 23. an upper groove; 24. rotating the bracket; 25. rotating and supporting; 26. a reinforcing bar; 27. a limiting sheet; 28. a protective cover; 29. a screw; 30. cushion blocks; 31. a dial.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

As shown in figures 1 to 8, the pipe cutting device of the invention comprises a workbench 1, supporting legs 2, reinforcing beams 3, convex blocks 4, a screw 5, a gear 6, a baffle 7, a double gear 8, a hinge 9, a rotary disk 10, a bracket 11, sliding supporting legs 12, pipe holes 13, a fixed support 14, a sliding fixing device 15, a cylinder 16, a piston 17, a motor 18, a transmission rod 19 and a blade 20, wherein the supporting legs 2 are arranged at four corners of the bottom end of the workbench 1, the top ends of the supporting legs 2 are connected with the bottom end of the workbench 1, the reinforcing beams 3 are arranged between the two groups of supporting legs 2, two ends of the reinforcing beams 3 are respectively connected with the inner sides of the supporting legs 2, two groups of convex blocks 4 are respectively arranged at the front and rear ends of the workbench 1, the inner sides of the convex blocks 4 are connected with the outer side of the workbench 1, the screw 5 is arranged between the two groups of convex blocks, the bottom end of the workbench 1 is provided with two groups of baffles 7, the top ends of the baffles 7 are connected with the bottom end of the workbench 1, the double gears 8 are positioned between the two groups of baffles 7, two ends of the double gears 8 are respectively rotatably connected with the inner sides of the baffles 7, two groups of gears 6 are respectively connected with the double gears 8 through hinges 9, a transmission shaft at the right end of the double gears 8 penetrates through the baffles 7 to be connected with the left end of a rotating disk 10, the right end of the rotating disk 10 is provided with a rotating handle which can drive the double gears 8 to rotate, two groups of screw rods 5 are driven to synchronously rotate through the hinges 9, two sides of the bottom end of a support 11 are respectively provided with sliding support legs 12, the top ends of the sliding support legs 12 are connected with the bottom end of the support 11, the bottom parts of the sliding support legs 12 are provided with threaded holes, the threaded holes at the bottom, the bottom end of a fixed support 14 is connected with the top end of the workbench 1, the top end of the fixed support 14 is flush with the top end of the bracket 11, the top end of a cylinder 16 is connected with the bottom end of a sliding fixing device 15, the cylinder 16 is connected with an air pump, the bottom end of the cylinder 16 is connected with the top end of a piston 17 in a sliding manner, the top end of the piston 17 can slide up and down at the bottom end of the cylinder 16, the left end of the piston 17 is connected with the right end of a motor 18, the motor 18 is connected with a power supply, the right output end of the motor 18 is connected with a; an operator measures the length of a pipe to be cut, then holds a rotary handle to rotate a rotary disk 10, drives two groups of screw rods 5 to synchronously rotate through a double gear 8, adjusts a support 11 to a proper position, then places the pipe on the top end of the support 11, the bottom end of the pipe is respectively contacted with the support 11 and the top end of a fixed support 14, then adjusts a blade 20 to the top end of the pipe through a sliding fixing device 15, then starts a cylinder 16, presses a piston 17 downwards until the bottom end of the blade 20 is just contacted with the top end of the pipe, then energizes a motor 18, outputs power to the right end of the motor 18, drives the blade 20 to rotate at a high speed through a transmission rod 19, cuts off the pipe through the blade 20, then controls the piston 17 to ascend through the cylinder 16, closes the motor 18, stops rotating the blade 20, takes off the cut pipe, and can replace a manual cutting tool to cut off the pipe, make section department more level and smooth, avoid buyer to carry out the secondary cutting because of the installation is not gone up to the device cuts off very fast, and work efficiency is high, has improved the practicality.

The invention relates to a pipe cutting device, which further comprises an extension plate 22, a rotating support 24 and a rotating support 25, wherein two parallel sliding plates 21 are arranged at the bottom end of a workbench 1, the top end of each sliding plate 21 is connected with the bottom end of the workbench 1, the two ends of each extension plate 22 are respectively connected with the inner sides of the corresponding sliding plates 21 in a sliding manner, the extension plate 22 can slide left and right on the corresponding sliding plate 21, an upper groove 23 is formed in the top end of each extension plate 22, the rotating support 24 is positioned in the corresponding upper groove 23, the left end of each rotating support 24 is rotatably connected with the left part of the corresponding upper groove 23, when the rotating support 24 is erected, the top end of each rotating support 24 is flush with the top end of a pipe hole 13, when the rotating support 24 is laid flat, the top end of each rotating support 24 is lower than the top end of the corresponding extension plate 22, the bottom end of each extension plate 22 is provided with, when the rotary support 25 is positioned in the groove, the rotary support 25 cannot fall out of the groove by locking of the locking device; when waiting to cut tubular product longer, can pull out extension board 22, open the locking device of extension board 22 bottom, open swivel support 25, make swivel support 25 bottom and ground contact, take out swivel support 24 from upper groove 23, then will grow out on the tubular product on workstation 1 top is placed swivel support 24, can make longer tubular product do not influence when cutting off and cut off the quality, make section department cutting neat, improved the practicality.

The pipe cutting device further comprises a reinforcing rod 26, the reinforcing rod 26 is located between the two groups of convex blocks 4, the reinforcing rod 26 is located on the upper side of the rotary support 25, two ends of the reinforcing rod 26 are respectively connected with the inner sides of the convex blocks 4, through holes are formed in the upper portions of the sliding support legs 12, the through holes in the upper portions of the sliding support legs 12 are concentrically connected with the reinforcing rod 26, and the sliding support legs 12 can slide left and right on the reinforcing rod 26; the cutting device only has the lead screw 5 as the support of support 11, has long led to lead screw 5 to warp inefficacy easily, and through setting up stiffener 26, accessible stiffener 26 improves the holding power of support 11, improves lead screw 5 life, has improved the practicality.

According to the pipe cutting device, the limiting piece 27 is arranged at the right part of the reinforcing rod 26, and the limiting piece 27 is sleeved on the reinforcing rod 26; when the rotating disc 10 is rotated, the sliding support leg 12 slides rightwards, so that the right end of the sliding support leg 12 is easy to collide with the gear 6, parts can be damaged after multiple collisions, the sliding support leg 12 can move to the position of the limiting piece 27 through the limiting piece 27 to be automatically stopped and cannot move rightwards continuously, the sliding support leg 12 is prevented from colliding with the gear 6, and the limiting performance is improved.

According to the pipe cutting device, the right end of the piston 17 is provided with the protective cover 28, the left end of the protective cover 28 is connected with the right end of the piston 17, part of the blades 20 are positioned in the protective cover 28, and the blades 20 are not in contact with the protective cover 28; when the device operates, the blade 20 rotates at a high speed, because the blade 20 is exposed outside, potential safety hazards exist on the mechanical articles of operators, most of the blades 20 are wrapped by the protective cover 28, the safety threat to the outside is reduced, and the safety protection performance is improved.

The pipe cutting device further comprises a screw 29 and a cushion block 30, the bottom end of each group of supporting legs 2 is provided with a threaded hole, the top end of the screw 29 is connected with the threaded hole at the bottom end of each supporting leg 2 in a matched mode, the bottom end of the screw 29 is rotatably connected with the top end of the cushion block 30, the bottom end of the cushion block 30 is in contact with the ground, and the height of each supporting leg 2 can be adjusted by rotating the screw 29; the device is best in the horizontality when the operation, just can guarantee to the regularity of tubular product cutting, adjusts the height of supporting leg 2 through rotatory screw 29 to make workstation 1 be in the horizontality, improved the practicality.

According to the pipe cutting device, the cushion block 30 is set to be a shock pad; when the blade 20 cuts the tubular product in-process, can produce great vibrations, through setting cushion 30 to the shock pad, the shock pad can absorb the vibrations that some devices produced, improves device life, has improved the practicality.

According to the pipe cutting device, the reinforcing rod 26 is provided with the dial 31, and the bottom end of the dial 31 is connected with the top end of the reinforcing rod 26; by arranging the dial 31, an operator can be replaced to fix distance measurement, and the rotary disk 10 can be directly rotated to read the dial 31, so that convenience is improved.

The invention relates to a pipe cutting device, which is characterized in that when in use, firstly an operator adjusts the height of a supporting leg 2 by rotating a rotary bracket 24, further adjusts a workbench 1 to be in a horizontal state, then measures the length of a pipe to be cut, then holds a rotary handle to rotate a rotary disk 10, drives two groups of screw rods 5 to synchronously rotate through a double gear 8, reads a numerical value on a protective cover 28, adjusts the bracket 11 to a proper position, then places the pipe at the top end of the bracket 11, the bottom end of the pipe is respectively contacted with the bracket 11 and the top end of a fixed support 14, if the pipe is longer, pulls out an extension plate 22, opens a locking device at the bottom end of the extension plate 22, opens a rotary support 25, enables the bottom end of the rotary support 25 to be contacted with the ground, takes out the rotary bracket 24 from an upper groove 23, then places the pipe which extends out of the top end of the workbench 1, the cutting quality of a long pipe is not affected when the long pipe is cut off, the cut part is cut neatly, the blade 20 is adjusted to the top end of the pipe through the sliding fixing device 15, the air cylinder 16 is started, the piston 17 is pressed downwards until the bottom end of the blade 20 is just contacted with the top end of the pipe, the motor 18 is powered on, the right end of the motor 18 outputs power, the blade 20 is driven to rotate at a high speed through the transmission rod 19, the pipe is cut off by the blade 20, the piston 17 is controlled to ascend through the air cylinder 16, the motor 18 is turned off, the blade 20 stops rotating, and the cut pipe is taken off.

According to the pipe cutting device, the installation mode, the connection mode or the arrangement mode are common mechanical modes, and the pipe cutting device can be implemented as long as the beneficial effects of the pipe cutting device can be achieved; the motor of the pipe cutting device is purchased from the market, and technicians in the industry only need to install and operate the motor according to the attached operating instructions.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A pipe cutting device is characterized by comprising a workbench (1), supporting legs (2), reinforcing beams (3), convex blocks (4), a lead screw (5), a gear (6), a baffle (7), double gears (8), a hinge (9), a rotary disk (10), a support (11), sliding supporting legs (12), pipe holes (13), a fixed support (14), a sliding fixing device (15), a cylinder (16), a piston (17), a motor (18), a transmission rod (19) and blades (20), wherein the four corners of the bottom end of the workbench (1) are respectively provided with the supporting legs (2), the top ends of the supporting legs (2) are connected with the bottom end of the workbench (1), the reinforcing beams (3) are arranged between the two groups of supporting legs (2), the two ends of each reinforcing beam (3) are respectively connected with the inner sides of the supporting legs (2), the front end and the rear end of the workbench (1) are respectively provided, the inner sides of the convex blocks (4) are connected with the outer side of the workbench (1), a lead screw (5) is arranged between every two groups of convex blocks (4), two ends of the lead screw (5) are respectively rotatably connected with the inner sides of the convex blocks (4), gears (6) are sleeved on the lead screw (5), two groups of baffles (7) are arranged at the bottom end of the workbench (1), the top ends of the baffles (7) are connected with the bottom end of the workbench (1), double gears (8) are positioned between the two groups of baffles (7), two ends of the double gears (8) are respectively rotatably connected with the inner sides of the baffles (7), the two groups of gears (6) are respectively connected with the double gears (8) through hinges (9), a transmission shaft at the right end of the double gears (8) penetrates through the baffles (7) to be connected with the left end of the rotating disk (10), a rotating handle is arranged at the right end of the rotating disk (10), the rotating handle can drive, two sides of the bottom end of a support (11) are respectively provided with a sliding support leg (12), the top end of the sliding support leg (12) is connected with the bottom end of the support (11), the bottom of the sliding support leg (12) is provided with a threaded hole, the threaded hole at the bottom of the sliding support leg (12) is connected with a lead screw (5) in a matching way, the sliding support leg (12) can slide left and right on the lead screw (5), the top end of the support (11) is provided with a pipe hole (13), a fixed support (14) is positioned at the left side of the support (11), the bottom end of the fixed support (14) is connected with the top end of a workbench (1), the top end of the fixed support (14) is flush with the top end of the support (11), the top end of a cylinder (16) is connected with the bottom end of a sliding fixing device (15), the cylinder (16) is connected with an air pump, the bottom end of the cylinder (16) is, the motor (18) is connected with a power supply, the output end of the right part of the motor (18) is connected with the transmission rod (19), and the right end of the transmission rod (19) penetrates through the piston (17) to be connected with the left end of the blade (20).

2. The pipe cutting device according to claim 1, further comprising an extension plate (22), a rotating bracket (24) and a rotating support (25), wherein two parallel sliding plates (21) are arranged at the bottom end of the workbench (1), the top end of each sliding plate (21) is connected with the bottom end of the workbench (1), two ends of each extension plate (22) are respectively connected with the inner sides of the sliding plates (21) in a sliding manner, the extension plates (22) can slide on the sliding plates (21) from left to right, an upper groove (23) is arranged at the top end of each extension plate (22), the rotating bracket (24) is positioned in the upper groove (23), the left end of each rotating bracket (24) is rotatably connected with the left part of the upper groove (23), when the rotating bracket (24) is erected, the top end of each rotating bracket (24) is flush with the top end of the pipe hole (13), and when the rotating bracket (24) is laid flat, the top end of each rotating bracket (24), the bottom end of the extension plate (22) is provided with two groups of grooves, the rotary support (25) is positioned in the groove at the bottom end of the extension plate (22), the left end of the rotary support (25) is rotatably connected with the left end of the groove, the bottom end of the extension plate (22) is provided with a locking device, and when the rotary support (25) is positioned in the groove, the rotary support (25) cannot fall out of the groove through locking of the locking device.

3. The pipe cutting device according to claim 2, further comprising a reinforcing rod (26), wherein the reinforcing rod (26) is located between the two sets of the protrusions (4), the reinforcing rod (26) is located on the upper side of the rotating support (25), two ends of the reinforcing rod (26) are respectively connected with the inner sides of the protrusions (4), a through hole is formed in the upper portion of the sliding leg (12), the through hole in the upper portion of the sliding leg (12) is concentrically connected with the reinforcing rod (26), and the sliding leg (12) can slide left and right on the reinforcing rod (26).

4. A pipe cutting apparatus according to claim 3, wherein the right portion of the reinforcing rod (26) is provided with a stopper piece (27), and the stopper piece (27) is fitted over the reinforcing rod (26).

5. A pipe cutting apparatus according to claim 4, wherein the right end of the piston (17) is provided with a guard (28), the left end of the guard (28) is connected to the right end of the piston (17), part of the blade (20) is located in the guard (28), and the blade (20) is free from contact with the guard (28).

6. The pipe cutting device according to claim 5, further comprising a screw (29) and a cushion block (30), wherein the bottom end of each group of support legs (2) is provided with a threaded hole, the top end of the screw (29) is in fit connection with the threaded hole at the bottom end of the support leg (2), the bottom end of the screw (29) is rotatably connected with the top end of the cushion block (30), the bottom end of the cushion block (30) is in contact with the ground, and the height of the support leg (2) can be adjusted by rotating the screw (29).

7. A pipe cutting apparatus as claimed in claim 6, wherein the spacer (30) is provided as a shock absorber.

8. A pipe cutting device as claimed in claim 7, wherein the reinforcing bar (26) is provided with a dial (31), and the bottom end of the dial (31) is connected to the top end of the reinforcing bar (26).