CN117655174A - Auxiliary device for bent pipe - Google Patents

Abstract

The invention relates to the technical field of bent pipes, in particular to an auxiliary bent pipe device which comprises a bent pipe unit, a bent pipe unit and a bent pipe unit, wherein the bent pipe unit comprises a bracket, a first die arranged on the bracket, a second die arranged on the bracket, a hydraulic device arranged on the second die, a supporting frame arranged on the bracket and a pipe body arranged on the supporting frame; the auxiliary unit comprises a clamping assembly arranged on the first die, a pressing assembly arranged on the first die and a limiting assembly arranged on the first die, and the pipe body in the bending process can be fastened and clamped gradually through the adjusting unit, so that the pipe body in the bending process is not required to be manually supported, the pipe body is not easy to turn over during bending, the bending effect is improved, the adjusting unit is convenient for personnel to adjust and install, the labor intensity can be reduced, and the working efficiency is improved.

Description

Auxiliary device for bent pipe

Technical Field

The invention relates to the technical field of bent pipes, in particular to an auxiliary device for bent pipes.

Background

The bending pipe is bent by adopting complete bending equipment, and is divided into two processes of cold stewing and hot pushing, namely, a machine device and a pipeline, most of the bending pipe is used for conveying oil, gas, transfusion, engineering bridge construction and the like, when bending is carried out, a metal pipe to be processed is required to be placed in a clamp of the bending pipe, a corresponding auxiliary bending pipe die is selected according to actual requirements to realize the design of a bending shape, and after the pipe is clamped, torque is applied to a clamping piece through adjusting a pipe bender transmission mechanism, so that the metal pipe is gradually deformed and the bending process is completed;

when a general pipeline is bent, the pipeline is free of a supporting mechanism, and the force of the bent pipe is easy to cause the pipeline to turn over in the process of bending the pipe, so that the pipe bending effect is affected.

Disclosure of Invention

This section is intended to outline some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description summary and in the title of the application, to avoid obscuring the purpose of this section, the description summary and the title of the invention, which should not be used to limit the scope of the invention.

The present invention has been made in view of the above-described problem of the pipe having no supporting mechanism.

It is therefore an object of the present invention to provide an auxiliary device for bending pipes.

In order to solve the technical problems, the invention provides the following technical scheme: the auxiliary device for the bent pipe comprises a bent pipe unit, a bending unit and a bending unit, wherein the bent pipe unit comprises a bracket, a first die arranged on the bracket, a second die arranged on the bracket, a hydraulic device arranged on the second die, a supporting frame arranged on the bracket and a pipe body arranged on the supporting frame; the auxiliary unit comprises a clamping assembly arranged on the first die, a pressing assembly arranged on the first die and a limiting assembly arranged on the first die.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: the clamping assembly comprises a sliding groove arranged on the first die, a sliding plate arranged on the sliding groove, a clamping plate arranged on the sliding plate, a rolling assembly arranged on the clamping plate, a connecting plate arranged on the sliding plate and a restoring spring arranged on the connecting plate.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: the pressing assembly comprises a touch piece arranged on the first die and a rolling piece arranged on the first die.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: the touch piece comprises a touch rod arranged on the first die and a toothed plate arranged on the touch rod.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: the winding piece comprises a rotating shaft arranged on the first die, a gear arranged on the rotating shaft, a winding wheel arranged on the rotating shaft, and a pull rope arranged on the winding wheel and connected with the connecting plate.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: the limiting assembly comprises a fitting piece arranged on the first die and a shrinkage piece arranged on the fitting piece.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: the laminating piece comprises a supporting block arranged on the first die, a containing block arranged on the supporting block, a compressing spring arranged on the containing block, a fixing plate arranged on the compressing spring and an inserting block arranged on the fixing plate.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: the shrink piece is including setting up the first connecting plate on the fixed plate, setting is in first bending rod on the first connecting plate, setting is in second bending rod on the first bending rod, setting is in movable block on the first bending rod, setting are in run through the pole on the movable block, and setting is in the second connecting plate on the second bending rod.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: also included is a method of manufacturing a semiconductor device,

the adjusting unit comprises a workbench, supporting legs arranged on the workbench, a telescopic rod arranged on the workbench and connected with the bracket, and a rotating assembly arranged on the workbench.

As a preferable mode of the pipe bending auxiliary device of the invention, wherein: the rotating assembly comprises an extending plate arranged on the workbench, an internal thread pipe arranged on the extending plate and an external thread rod arranged on the internal thread pipe.

The invention has the beneficial effects that: according to the invention, the pipe body in the bending process can be gradually fastened and clamped through the adjusting unit, so that the pipe body in the bending process does not need to be manually supported, and the pipe body is not easy to turn over in the bending process, so that the bending effect is improved, and the adjusting unit is convenient for personnel to adjust and install, the labor intensity can be reduced, and the working efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is an overall schematic diagram of an auxiliary device for bending pipes.

Fig. 2 is a schematic view of a first mold of the auxiliary device for bending pipes.

Fig. 3 is a schematic view of an auxiliary unit of the pipe bending auxiliary device.

Fig. 4 is an enlarged view at a in fig. 3.

Fig. 5 is a schematic view of a receiving block of the elbow attachment.

Fig. 6 is an enlarged view at B in fig. 5.

Fig. 7 is a schematic view of an adjusting unit of the auxiliary device for bending pipes.

Detailed Description

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present invention is not limited to the specific embodiments disclosed below.

Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic can be included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

Further, in describing the embodiments of the present invention in detail, the cross-sectional view of the device structure is not partially enlarged to a general scale for convenience of description, and the schematic is only an example, which should not limit the scope of protection of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.

Example 1

Referring to fig. 1, in a first embodiment of the present invention, an auxiliary device for bending a pipe is provided, which includes a pipe bending unit 100 and an auxiliary unit 200, wherein the pipe bending unit 100 is used for bending a placed pipe, the auxiliary unit 200 is mounted on the pipe bending unit 100, so as to improve the pipe bending effect of the pipe bending unit 100 and facilitate the use of the pipe bending unit 100.

Specifically, the pipe bending unit 100 includes a bracket 101, the bracket 101 is formed by a section of channel steel, the first die 102 is arranged at the top of the bracket 101, the first die 102 is formed by two groups of broken die blocks, a bending point of a pipe body 106 is located at a breaking position of the first die 102, a second die 103 is arranged on the bracket 101, the second die 103 is located at one side of the first die 102, the second die 103 is matched with the first die 102, when the second die 103 moves, the pipe body 106 is bent and formed on the first die 102 under the extrusion of the second die 103, a hydraulic device 104 is arranged on the second die 103, the hydraulic device 104 is a mechanical device for bending a metal pipe, the shape and the angle of the metal pipe are mainly changed through the application of force and heat, a supporting frame 105 is arranged on the bracket 101, the pipe body 106 is arranged on the supporting frame 105, when the pipe body 106 is placed, the second die 103 is driven by the hydraulic device 104 to move, so that the pipe body 106 is gradually bent and formed on the first die 102 under the extrusion of the second die 103, and the supporting frame 105 is bent and the pipe body 106 is bent.

The operation process comprises the following steps: the first die 102 is composed of two groups of broken die blocks, under the extrusion of the second die 103, the bending point of the pipe body 106 is located at the broken position of the first die 102, when the pipe body 106 is placed, the pipe body 106 is placed between the first die 102 and the second die 103, then the hydraulic device 104 drives the second die 103 to move, so that the second die 103 gradually extrudes and bends the pipe body 106 on the first die 102, and when the pipe body 106 bends, the support frame 105 is arranged, so that the bent pipe body 106 can be supported by the support frame 105, and the pipe body 106 outside the bending position does not need to be supported manually.

Example 2

Referring to fig. 1 to 6, a second embodiment of the present invention is different from the first embodiment in that: the auxiliary unit 200 comprises a clamping assembly 201 arranged on the first die 102, a pressing assembly 202 arranged on the first die 102 and a limiting assembly 203 arranged on the first die 102, wherein the clamping assembly 201 is used for clamping the pipe body 106 in the bending process, so that the pipe body 106 is not easy to turn over when being stressed.

Specifically, the clamping assembly 201 comprises four groups of sliding grooves 201a formed on the first die 102, a group of sliding plates 201b are mounted on the inner wall of each group of sliding grooves 201a, a clamping plate 201c is mounted on the outer wall of one side of each sliding plate 201b, a rolling assembly 201d is arranged on each clamping plate 201c, each rolling assembly 201d comprises a sliding rail 201d-1 mounted on each clamping plate 201c, a sliding plate 201d-2 mounted on each sliding rail 201d-1, the sliding plate 201d-2 can slide on each sliding rail 201d-1, a fixed shaft 201d-3 is mounted on the outer wall of each sliding plate 201d-2, the fixed shaft 201d-3 is connected with the sliding plate 201d-2 through a bearing, a concave plate 201d-4 is mounted at one end of each fixed shaft 201d-3, a roller 201d-5 is mounted on the inner wall of each concave plate 201d-4, and when the tube 106 is subjected to stress bending, the clamping plate 201c is forced to drive the rolling assembly 201d to move, so that the roller 201d-5 of the rolling assembly 201d is in contact with the pipe body 106, the pipe body 106 is slightly clamped by the roller 201d-5, the clamping force is increased along with the bending strengthening, the sliding plate 201d-2 of the pipe body 106 slides on the sliding rail 201d-1 along with the bending during the bending, the fixed shaft 201d-3 is forced to rotate, the roller 201d-5 always clamps the pipe body 106, the pipe body 106 is not easy to overturn, the connecting plate 201e is arranged on the outer wall of the other side of the sliding plate 201b, the connecting plate 201e is positioned in the first die 102, the restoring spring 201f is arranged on the connecting plate 201e, and the restoring spring 201f is used for restoring the moving connecting plate 201 e.

Further, the pressing assembly 202 includes a pressing member 202a disposed on the first mold 102, a rolling member 202b disposed on the first mold 102, when the tube 106 is bent, the tube 106 is pressed against the pressing member 202a, the pressing member 202a is pressed by the tube 106 to move, the pressing member 202a drives the rolling member 202b to drive, so that the rolling member 202b drives the connecting plate 201e to move, the connecting plate 201e moves to drive the sliding plate 201b to move, the sliding plate 201b moves to drive the clamping plate 201c to move, and the clamping plate 201c moves to clamp the tube 106 by the roller 201d-5 of the rolling assembly 201 d.

Further, the touch member 202a includes two sets of touch bars 202a-1 disposed on the first mold 102, the touch bars 202a-1 extend from the outside of the first mold 102 into the inside of the first mold 102 and extend to one side of the winding member 202b, the toothed plate 202a-2 is mounted on one end of the touch bar 202a-1, when the pipe bends, the pipe gradually touches the touch bars 202a-1, the touch bars 202a-1 drive the toothed plate 202a-2 to move, the toothed plate 202a-2 moves to drive the winding member 202b to drive the connecting plate 201e to move.

Further, the winding member 202b includes two sets of rotating shafts 202b-1 disposed on the first mold 102, each set of rotating shafts 202b-1 is mounted on an inner wall of the first mold 102 through a bearing, each set of rotating shafts 202b-1 is mounted with a set of gears 202b-2, the gears 202b-2 are meshed with the toothed plate 202a-2, a winding wheel 202b-3 disposed on the rotating shafts 202b-1, a pull rope 202b-4 disposed on the winding wheel 202b-3 and connected with the connecting plate 201e, two sets of pull ropes 202b-4 are disposed on a surface of one set of winding wheel 202b-3, each set of pull ropes 202b-4 is connected with one set of connecting plate 201e, the toothed plate 202a-2 moves the transmission gears 202b-2 to rotate, the gears 202b-2 rotate to drive the rotating shafts 202b-1 to rotate, the rotating shafts 202b-1 drive the winding wheel 202b-3 to rotate to wind the two sets of pull ropes 202b-4 simultaneously, and simultaneously pull the connecting plate 201e pulls the connecting plate 201c to drive the connecting plate 201c to move to clamp the rolling member 201 c.

Further, the limiting component 203 includes a fitting piece 203a disposed on the first mold 102, the fitting piece 203a is clamped on the toothed plate 202a-2, so that the toothed plate 202a-2 can only move unidirectionally, and the winding wheel 202b-3 driven by rotation can only wind the pull rope 202b-4, so that after the pipe 106 is bent, the second mold 103 is restored, when the pipe 106 is not extruded, the pipe 106 is still clamped by the clamping plate 201c, so that the bent portion of the pipe 106 can be exposed in advance for being observed by a worker, if the pipe 106 needs to be bent again, the hydraulic device 104 can be touched again for bending, and the shrinking piece 203b disposed on the fitting piece 203a can be used for pulling the fitting piece 203a, so that the fitting piece 203a is not clamped on the toothed plate 202a-2, and when the second mold 103 is not pressed to hold the pipe 106, the pipe 106 can not be fastened and clamped again.

Further, the attaching member 203a includes a supporting block 203a-1 disposed on the first mold 102, a receiving block 203a-2 disposed on the supporting block 203a-1, the supporting block 203a-1 has a mounting effect on the receiving block 203a-2, such that the mounting block is mounted on one side of the toothed plate 202a-2 and is located on a side close to the gear 202b-2, a pressing spring 203a-3 disposed on the receiving block 203a-2, a fixing plate 203a-4 disposed on the pressing spring 203a-3, two groups of inserting blocks 203a-5 disposed on the fixing plate 203a-4, the pressing spring 203a-3 presses the fixing plate 203a-4, such that the two groups of inserting blocks 203a-5 on the fixing plate 203a-4 are embedded into tooth grooves of the toothed plate 202a-2, and the inserting blocks 203a-5 are provided with inclined surfaces, such that the inclined surfaces face one side of the contact rod 202a-1, so that the toothed plate 202a-2 can move toward one end of the gear 202b-2, and the toothed plate 202a-2 can not be moved, such that the pull rope 202b-3 can be easily and the manual rolling assembly 201c can not be held, and the manual rolling assembly 201c can not be easily and easily rolled up.

Further, the contracting member 203b includes a first connection plate 203b-1 provided on the fixed plate 203a-4, a first bending rod 203b-2 provided on the first connection plate 203b-1, the first bending rod 203b-2 is mounted on the first connection plate 203b-1 through a pin shaft so that the first bending rod 203b-2 can move on the first connection plate 203b-1, a second bending plate 203b-3 provided on the first bending rod 203b-2, the second bending plate 203b-3 is connected on the first bending rod 203b-2 through a pin shaft, and the movable block 203b-4 is also mounted on a pin shaft connecting the first bending rod 203b-2 and the second bending plate 203b-3, a penetrating rod 203b-5 provided on the movable block 203b-4, the penetrating rod 203b-5 extends from the movable block 203b-4 to the outside of the first mold 102, and the aperture of the penetrating rod 203b-5 and the penetrating hole of the first mold 102 is larger than the diameter of the penetrating rod 203b-5, so that the penetrating rod 203b-5 has a moving space, when the pipe body 106 needs to be removed, the penetrating rod 203b-5 is pressed, the penetrating rod 203b-5 presses the movable block 203b-4, the movable block 203b-4 is stressed on the pin shaft between the first bending rod 203b-2 and the second bending plate 203b-3, so that the first bending rod 203b-2 and the second bending plate 203b-3 bend, so that the first bending rod 203b-2 drives the fixed plate 203a-4 to move, so that the insert block 203a-5 of the fixed plate 203a-4 is separated from the toothed plate 202a-2, at this time, the restoring spring 201f can restore the clamping plate 201c, at this time, the clamping of the bent pipe body 106 can be loosened, the second connection plate 203b-6 is disposed on the second bending rod, and the second bending plate 203b-3 is also connected to the second connection plate 203b-6 through a pin.

The rest of the structure is the same as in embodiment 1.

The operation process comprises the following steps: when the pipe 106 is not bent, the rolling assembly 201d makes the pipe 106 be wrapped by the two groups of rolling assemblies 201d, at this time, the pipe 106 is not easy to move, the toothed plate 202a-2 moves to drive the gear 202b-2 to rotate, the gear 202b-2 rotates to drive the rotating shaft 202b-1 to rotate, the rotating shaft 202b-1 rotates to drive the rolling wheel 202b-3 to rotate, the rolling wheel 202b-3 rotates to wind the two groups of pull ropes 202b-4 simultaneously, the pull ropes 202b-4 are wound, the connecting plate 201e is pulled, when the pipe is bent, the pipe 106 gradually touches the touch rod 202a-1, the touch rod 202a-1 drives the toothed plate 202a-2 to move, the connecting plate 201e moves to drive the sliding plate 201b to move, and the sliding plate 201b moves to drive the clamping plate 201c to move, so that the clamping force of the rolling assembly 201d on the clamping plate 201c to the pipe 106 is gradually increased, in the bending process, the pipe body 106 is also clamped tightly, so that the pipe body 106 is not easy to turn over, the bending effect is ensured, and when the second die 103 is reset after bending, the pipe body 106 is clamped and still kept, so that the bending effect can be checked after the pipe body 106 is bent, if bending is not in place, pressing bending can be performed again, at the moment, the clamping and keeping of the pipe body 106 can keep the original bending point, the original bending point is not changed, the bending effect is ensured, the subsequent bending effect is ensured, when the pipe body 106 is required to be unclamped, the penetrating rod 203b-5 is pressed, the penetrating rod 203b-5 presses the movable block 203b-4, the movable block 203b-4 is stressed on a pin shaft between the first bending rod 203b-2 and the second bending plate 203b-3, the first bending rod 203b-2 and the second bending plate 203b-3 are bent, so that the first bending rod 203b-2 drives the fixing plate 203a-4 to move, so that the insert block 203a-5 of the fixing plate 203a-4 is separated from the toothed plate 202a-2, and the restoring spring 201f can restore the clamping plate 201c, so that the tube 106 can be removed.

Example 3

Referring to fig. 7, a third embodiment of the present invention is shown, which is different from the above embodiment in that: still include, the adjustment unit 300, including workstation 301, workstation 301 is located the bottom side of return bend unit 100, sets up the supporting leg 302 on workstation 301, and the telescopic link 303 of setting on workstation 301 and being connected with bracket 101, telescopic link 303 play the supporting role to bracket 101, and the rotatory subassembly 304 of setting on workstation 301 is used for carrying out the rising with bracket 101 to rotatory subassembly 304 for the personnel of different heights all can be comfortable carry out the return bend work.

Specifically, the rotating assembly 304 includes an extension plate 304a disposed on the workbench 301, the extension plate 304a mounts the internally threaded tube, an internally threaded tube 304b disposed on the extension plate 304a, and an externally threaded rod 304c disposed on the internally threaded tube 304b, when the working height is required to be adjusted according to the height of the operator, the externally threaded rod 304c is rotated, and the externally threaded rod 304c is rotationally moved on the internally threaded tube 304b, so that the externally threaded rod 304c gradually pushes the bracket 101 upwards, thereby completing the height adjustment, and the adjusting unit 300 is convenient for personnel to adjust and mount, can reduce the labor intensity, and improve the working efficiency.

The rest of the structure is the same as in embodiment 2.

The operation process comprises the following steps: the workbench 301 is located at the bottom side of the pipe bending unit 100, the telescopic rod 303 plays a supporting role on the bracket 101, when the working height is required to be adjusted according to a worker, the external threaded rod 304c is rotated and moved on the internal threaded pipe 304b, and the bracket 101 is gradually pushed upwards by the external threaded rod 304c, so that the height adjustment is completed.

It should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered in the scope of the claims of the present invention.

Claims (10)

1. An auxiliary device for bending pipes, which is characterized in that: comprising the steps of (a) a step of,

a pipe bending unit (100) comprising a bracket (101), a first die (102) arranged on the bracket (101), a second die (103) arranged on the bracket (101), a hydraulic device (104) arranged on the second die (103), a supporting frame (105) arranged on the bracket (101), and a pipe body (106) arranged on the supporting frame (105);

an auxiliary unit (200) comprising a clamping assembly (201) arranged on the first mould (102), a pressing assembly (202) arranged on the first mould (102), and a limiting assembly (203) arranged on the first mould (102).

2. The elbow attachment of claim 1, wherein: the clamping assembly (201) comprises a sliding groove (201 a) arranged on the first die (102), a sliding plate (201 b) arranged on the sliding groove (201 a), a clamping plate (201 c) arranged on the sliding plate (201 b), a rolling assembly (201 d) arranged on the clamping plate (201 c), a connecting plate (201 e) arranged on the sliding plate (201 b) and a restoring spring (201 f) arranged on the connecting plate (201 e).

3. The elbow attachment of claim 2, wherein: the pressing assembly (202) includes a contact element (202 a) disposed on a first die (102), and a winding element (202 b) disposed on the first die (102).

4. A pipe bending assist device as claimed in claim 3, wherein: the contact element (202 a) comprises a contact rod (202 a-1) arranged on the first mould (102), and a toothed plate (202 a-2) arranged on the contact rod (202 a-1).

5. The elbow attachment of claim 4, wherein: the winding member (202 b) comprises a rotating shaft (202 b-1) arranged on the first die (102), a gear (202 b-2) arranged on the rotating shaft (202 b-1), a winding wheel (202 b-3) arranged on the rotating shaft (202 b-1), and a pull rope (202 b-4) arranged on the winding wheel (202 b-3) and connected with the connecting plate (201 e).

6. The elbow attachment of claim 1 or 5, wherein: the limiting assembly (203) comprises a fitting piece (203 a) arranged on the first die (102) and a shrinking piece (203 b) arranged on the fitting piece (203 a).

7. The elbow attachment of claim 6, wherein: the attaching member (203 a) includes a supporting block (203 a-1) provided on the first mold (102), a receiving block (203 a-2) provided on the supporting block (203 a-1), a pressing spring (203 a-3) provided on the receiving block (203 a-2), a fixing plate (203 a-4) provided on the pressing spring (203 a-3), and an inserting block (203 a-5) provided on the fixing plate (203 a-4).

8. The elbow attachment of claim 7, wherein: the contraction member (203 b) includes a first connection plate (203 b-1) provided on a fixed plate (203 a-4), a first bending rod (203 b-2) provided on the first connection plate (203 b-1), a second bending rod provided on the first bending rod (203 b-2), a movable block (203 b-4) provided on the first bending rod (203 b-2), a penetrating rod (203 b-5) provided on the movable block (203 b-4), and a second connection plate (203 b-6) provided on the second bending rod.

9. The elbow attachment of claim 8, wherein: also included is a method of manufacturing a semiconductor device,

an adjusting unit (300) comprises a workbench (301), a supporting leg (302) arranged on the workbench (301), a telescopic rod (303) arranged on the workbench (301) and connected with a bracket (101), and a rotating assembly (304) arranged on the workbench (301).

10. The elbow attachment of claim 9, wherein: the rotating assembly (304) comprises an extension plate (304 a) arranged on the workbench (301), an internally threaded tube (304 b) arranged on the extension plate (304 a), and an externally threaded rod (304 c) arranged on the internally threaded tube (304 b).