CN214789757U

CN214789757U - Firm in structure's antidetonation support

Info

Publication number: CN214789757U
Application number: CN202121236565.1U
Authority: CN
Inventors: 吴欢
Original assignee: Lu'an Jietu Seismic Technology Co ltd
Current assignee: Lu'an Jietu Seismic Technology Co ltd
Priority date: 2021-06-03
Filing date: 2021-06-03
Publication date: 2021-11-19
Anticipated expiration: 2031-06-03

Abstract

The utility model discloses a sound construction's antidetonation support relates to antidetonation support equipment technical field, which comprises a pipe body, be provided with first staple bolt and second staple bolt on the outer wall of body, first staple bolt is located the bottom of body outer wall, the second staple bolt is located the top of body outer wall, internal diameter and the external diameter looks adaptation of body after first staple bolt and the closed second staple bolt, all set up two first screw thread through-holes that the position is the same on the pterygoid lamina of first staple bolt and second staple bolt, first screw thread through-hole female connection has first fixed screw, the second staple bolt is kept away from the first main tributary vaulting pole of fixedly connected with on the hoop board of body, the installation notch has been seted up at the top of first main tributary vaulting pole. The utility model discloses have more firm and carry out antidetonation effect to the pipeline.

Description

Firm in structure's antidetonation support

Technical Field

The utility model relates to an antidetonation support technical field especially relates to a sound construction's antidetonation support.

Background

The anti-seismic support limits the displacement of the attached electromechanical engineering facilities, controls the vibration of the facilities and transmits the load to various components or devices on the bearing structure. The anti-seismic support gives reliable protection to building electromechanical engineering facilities in the earthquake and bears the earthquake action from any horizontal direction; the anti-seismic support is checked according to the load borne by the anti-seismic support; all the components constituting the anti-seismic support should be finished components, and the components for connecting the fasteners should be convenient to install.

The existing anti-seismic support mostly comprises a pipeline hoop, a locking device and a support frame, the pipeline is fixed through the pipeline hoop and the locking device, and the support frame connected with the pipeline hoop is connected with a mounting surface to provide an anti-seismic effect for the pipeline.

However, when the existing anti-seismic support resists the vibration force, the internal supporting component can be deviated or broken due to the excessively strong vibration, the reliability of the existing supporting component is low, and the potential safety hazard is increased.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the defects existing in the prior art and providing a firm anti-seismic support. The advantage lies in can be more firm carry out antidetonation to the pipeline.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

an anti-seismic support with a firm structure comprises a pipe body, wherein a first hoop and a second hoop are arranged on the outer wall of the pipe body, the first hoop is positioned at the bottom of the outer wall of the pipe body, the second hoop is positioned at the top of the outer wall of the pipe body, the inner diameter of the closed first hoop and the closed second hoop is matched with the outer diameter of the pipe body, two first threaded through holes with the same position are respectively arranged on wing plates of the first hoop and the second hoop, a first fixing screw is connected in the first threaded through holes in a threaded manner, a first main support rod is fixedly connected on a hoop plate of the second hoop, which is far away from the pipe body, the top of the first main support rod is provided with an installation notch, a second main support rod is installed in the installation notch in a sliding manner, a plurality of compression springs which are distributed at equal intervals are fixedly connected at the bottom of the installation notch and the top of the second main support rod, a fixed vertical plate is arranged at the top of the second main support rod, first connecting rods are fixedly connected between the top of the second main supporting rod and the same port at the bottom of the fixed vertical plate, and a plurality of first fixing screws distributed at equal intervals are arranged on the fixed vertical plate.

Through the technical scheme: when the anti-seismic support is used, the first hoop and the second hoop are closed to clamp and fix the pipe body, the first hoop and the second hoop are fixedly connected through the first fixing screws, the stability of clamping the pipe body is improved, the fixing vertical plate is further firmly fixed on the mounting surface through the first fixing screws, when earthquake and other vibration happen, the first compression spring between the first main support rod and the second main support rod resists earthquake elastically, the damage of the anti-seismic support caused by rigid earthquake resistance is avoided, and the firmness of the anti-seismic support is further improved.

The utility model discloses further set up to, the top of second main tributary vaulting pole is provided with the fixed diaphragm of fixed riser with the horizontality, be provided with the second set screw that a plurality of equidistance distributes on the fixed diaphragm, fixed riser's bottom central point puts and has seted up first draw-in groove, set up the second draw-in groove with first draw-in groove looks adaptation on the top of fixed diaphragm, fixed riser and fixed diaphragm joint mutually.

Through the technical scheme: the fixed transverse plate and the fixed vertical plate are clamped by the first clamping groove and the second clamping groove, so that an overall anti-seismic effect is formed between the fixed transverse plate and the fixed vertical plate, and the firmness of the anti-seismic support is further improved.

The utility model discloses further set up to, one side fixedly connected with staple bolt curb plate of second staple bolt, the first fixed block of one end fixedly connected with of body is kept away from to the staple bolt curb plate, the first flexible piece of one side fixedly connected with that fixed diaphragm bottom is close to the staple bolt curb plate, second installation notch has been seted up to first flexible piece bottom, slidable mounting has first connecting block in the second installation notch, the second compression spring that fixedly connected with a plurality of equidistance distributes between the top of first connecting block and the top of second installation notch, the bottom fixedly connected with second bracing piece of first connecting block, the bottom of second bracing piece and the top fixed connection of first fixed block, and the slope sets up between second bracing piece and the fixed diaphragm.

Through the technical scheme: the second support rod can form a more direct connection relation between the fixed transverse plate and the tube body, the anti-seismic effect of the fixed transverse plate on the tube body is improved, the second compression spring can perform elastic anti-seismic on the tube body, and a triangular stable shape is formed among the inclined second support rod, the first main support rod and the fixed transverse plate, so that the firmness of the anti-seismic support is improved.

The utility model discloses further set up to, the fixed riser is close to the equal fixedly connected with second connecting rod in one side both ends of staple bolt curb plate, and the second connecting rod keeps away from one side fixed connection that the other end of fixed riser and fixed diaphragm are close to the staple bolt curb plate.

Through the technical scheme: the second connecting rods are used for integrally reinforcing the fixed transverse plate, the fixed vertical plate and the second supporting rod, and the firmness of the anti-seismic support is further improved.

The utility model discloses further set up to, be provided with third staple bolt and fourth staple bolt on one side that the staple bolt curb plate was kept away from to the body, and third staple bolt and fourth staple bolt and first staple bolt and the perpendicular setting of second staple bolt, the internal diameter after third staple bolt and the closed fourth staple bolt and the external diameter looks adaptation of body, all set up two second screw thread through-holes that the position is the same on the pterygoid lamina of third staple bolt and fourth staple bolt, second screw thread through-hole female connection has the second set screw. .

Through the technical scheme: the bearing is shared to the body by the second fixture that forms between third staple bolt and the fourth staple bolt, and second fixture sets up with first fixture is perpendicular for the effort that the antidetonation support becomes the body more even, has further improved the fastness of antidetonation support.

The utility model discloses further set up to, equal fixed mounting has the second fixed block on the hoop board outer wall of third staple bolt and fourth staple bolt, the flexible piece of one side fixedly connected with second of staple bolt curb plate is kept away from to fixed diaphragm bottom, the third installation notch that two mirror images distribute is seted up to the bottom of the flexible piece of second, sliding connection has the second connecting block in the third installation notch, the third compression spring that a plurality of fixedly connected with equidistance distributes between the top of second connecting block and the top of third installation notch, the bottom fixedly connected with third bracing piece of second connecting block, the bottom of third bracing piece rather than adjacent second fixed block top fixed connection.

Through the technical scheme: form direct antidetonation mechanism through the third bracing piece between with second fixture and the fixed diaphragm, carry out elasticity antidetonation by third compression spring to the body, further guarantee that the body can not drop or rock to the fastness of whole antidetonation support has been improved.

The utility model discloses further set up to, the level sets up between third bracing piece and the first main tributary vaulting pole.

Through the technical scheme: longitudinal anti-seismic force is formed by the third supporting rod to the tube body, and the firmness of the whole anti-seismic support is improved.

The utility model discloses further set up to, all fix on the hoop plate inner wall of first staple bolt, second staple bolt, third staple bolt and fourth staple bolt and be provided with the antidetonation gasket.

Through the technical scheme: by antidetonation gasket and body direct contact, avoided causing the damage to the body at antidetonation in-process staple bolt, further improved the life of antidetonation support.

The utility model has the advantages that:

1. the utility model discloses, through setting up the body, first staple bolt, the second staple bolt, first fixed screw, first main tributary vaulting pole, the second main tributary vaulting pole, the head rod, fixed riser, first set screw and compression spring, when using, it is fixed with the body centre gripping by the closure of first staple bolt and second staple bolt, again with first staple bolt and second staple bolt fixed connection by first fixed screw, improve the stability to the body centre gripping, further will fix the firm fixing on the installation face of riser by first set screw, when vibrations such as earthquake take place, by the compression spring elasticity antidetonation between first main tributary vaulting pole and the second main tributary vaulting pole, avoid accomplishing the rigidity antidetonation and the antidetonation support that causes damages, the fastness of antidetonation support has further been improved.

2. The utility model discloses, through setting up fixed diaphragm, second set screw, first draw-in groove, the second draw-in groove, the staple bolt curb plate, first fixed block, first flexible piece, first connecting block, second compression spring and second bracing piece, by first draw-in groove and second draw-in groove with fixed diaphragm and fixed riser looks joint, make to form whole shock-resistant effect between fixed diaphragm and the fixed riser, form more direct relation of connection between will fixing diaphragm and the body by the second bracing piece again, improve the antidetonation effect of fixed diaphragm to the body, further carry out elasticity antidetonation by second compression spring to the body, further form triangle-shaped stable shape by between second bracing piece and first main tributary vaulting pole and the fixed diaphragm of slope, improve the fastness of antidetonation support.

3. The utility model discloses, through setting up the third staple bolt, the fourth staple bolt, the second fixed screw, the flexible piece of second, the second connecting block, third compression spring and third bracing piece, share the bearing to the body by the second fixture that forms between third staple bolt and the fourth staple bolt, and second fixture sets up with first fixture is perpendicular, make the effort that the shock-resistant support becomes more even to the body, carry out elasticity antidetonation by third compression spring to the body again, further form direct shock-resistant mechanism between with second fixture and the fixed diaphragm through the third bracing piece, further guarantee that the pipeline can not drop or rock, thereby whole shock-resistant support's fastness has been improved.

Drawings

Fig. 1 is a schematic structural view of a structurally firm anti-seismic support provided by the present invention;

fig. 2 is a schematic cross-sectional structural view of a first main support rod of a structurally sound anti-seismic support according to the present invention;

FIG. 3 is a schematic view of a cross-sectional structure of a fixed riser of a structurally sound anti-seismic support of the present invention;

fig. 4 is a schematic structural view of a cross section of a fixed transverse plate of the anti-seismic bracket with a firm structure provided by the utility model;

fig. 5 is a schematic view of the hoop structure of the anti-seismic support with a firm structure provided by the present invention;

fig. 6 is a schematic cross-sectional structure view of a first expansion block of a structurally firm anti-seismic support according to the present invention;

fig. 7 is the utility model provides a second telescopic block cross-sectional structure schematic diagram of firm in structure's antidetonation support.

In the figure: 1. a pipe body; 2. a first hoop; 3. a second hoop; 4. a first fixing screw; 5. a first main support bar; 6. a second main support bar; 7. an anti-seismic gasket; 8. a first connecting rod; 9. fixing a vertical plate; 10. a first set screw; 11. a second connecting rod; 12. fixing the transverse plate; 13. a second support bar; 14. a hoop side plate; 15. a first fixed block; 16. a second set screw; 17. a third support bar; 18. a third hoop; 19. a fourth hoop; 20. a second fixed block; 21. a second fixing screw; 22. a first compression spring; 23. a first card slot; 24. a second card slot; 25. a first telescopic block; 26. a second telescopic block; 27. a second compression spring; 28. a third compression spring; 29. a first connection block; 30. and a second connecting block.

Detailed Description

The technical solution of the present patent will be described in further detail with reference to the following embodiments.

Reference will now be made in detail to embodiments of the present patent, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present patent and are not to be construed as limiting the present patent.

In the description of this patent, it is to be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for the convenience of describing the patent and for the simplicity of description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the patent.

In the description of this patent, it is noted that unless otherwise specifically stated or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly and can include, for example, fixedly connected, disposed, detachably connected, disposed, or integrally connected and disposed. The specific meaning of the above terms in this patent may be understood by those of ordinary skill in the art as appropriate.

Referring to fig. 1-2, an anti-seismic support with a firm structure comprises a pipe body 1, wherein a first hoop 2 and a second hoop 3 are arranged on the outer wall of the pipe body 1, the first hoop 2 is positioned at the bottom of the outer wall of the pipe body 1, the second hoop 3 is positioned at the top of the outer wall of the pipe body 1, the inner diameter of the closed first hoop 2 and the closed second hoop 3 is matched with the outer diameter of the pipe body 1, two first threaded through holes with the same position are respectively arranged on wing plates of the first hoop 2 and the second hoop 3, a first fixing screw 4 is connected in the first threaded through hole in a threaded manner, a first main support rod 5 is fixedly connected on a hoop plate of the second hoop 3, which is far away from the pipe body 1, a mounting notch is arranged at the top of the first main support rod 5, a second main support rod 6 is slidably arranged in the mounting notch, a plurality of first compression springs 22 are fixedly connected at the bottom of the mounting notch and the top of the second main support rod 6, a fixed vertical plate 9 is arranged at the top of the second main supporting rod 6, first connecting rods 8 are fixedly connected between the top of the second main supporting rod 6 and the same port at the bottom of the fixed vertical plate 9, and a plurality of first fixing screws 10 distributed at equal intervals are arranged on the fixed vertical plate 9.

Referring to fig. 1-4, a fixed transverse plate 12 which is level with the fixed vertical plate 9 is arranged at the top of the second main support rod 6, a plurality of second fixing screws 16 distributed at equal intervals are arranged on the fixed transverse plate 12, a first clamping groove 23 is formed in the center of the bottom of the fixed vertical plate 9, a second clamping groove 24 which is matched with the first clamping groove 23 is formed in the top of the fixed transverse plate 12, the fixed vertical plate 9 is clamped with the fixed transverse plate 12, the fixed transverse plate 12 is clamped with the fixed vertical plate 9 through the first clamping groove 23 and the second clamping groove 24, so that an overall anti-seismic effect is formed between the fixed transverse plate 12 and the fixed vertical plate 9, and the firmness of the anti-seismic support is further improved.

Referring to fig. 1-7, one side of the second hoop 3 is fixedly connected with a hoop side plate 14, one end of the hoop side plate 14 away from the pipe body 1 is fixedly connected with a first fixed block 15, one side of the bottom of the fixed transverse plate 12 close to the hoop side plate 14 is fixedly connected with a first telescopic block 25, the bottom of the first telescopic block 25 is provided with a second installation notch, a first connecting block 29 is slidably installed in the second installation notch, a plurality of second compression springs 27 distributed equidistantly are fixedly connected between the top of the first connecting block 29 and the top of the second installation notch, the bottom of the first connecting block 29 is fixedly connected with a second supporting rod 13, the bottom of the second supporting rod 13 is fixedly connected with the top of the first fixed block 15, the second supporting rod 13 is obliquely arranged with the fixed transverse plate 12, the second supporting rod 13 forms a more direct connection relationship between the fixed transverse plate 12 and the pipe body 1, the anti-seismic effect of the fixing transverse plate 12 on the pipe body 1 is improved, the second compression spring 27 elastically resists the vibration of the pipe body 1, and a triangular stable shape is formed between the inclined second support rod 13, the first main support rod 5 and the fixing transverse plate 12, so that the firmness of the anti-seismic support is improved.

The equal fixedly connected with second connecting rod 11 in one side both ends that fixed riser 9 is close to staple bolt curb plate 14, and second connecting rod 11 keeps away from one side fixed connection that the other end of fixed riser 9 and fixed diaphragm 12 are close to staple bolt curb plate 14, is consolidated wholly by second connecting rod 11 between fixed diaphragm 12 and fixed riser 9 and the second bracing piece 13, further improves the fastness of antidetonation support.

Be provided with third staple bolt 18 and fourth staple bolt 19 on the one side that the staple bolt curb plate 14 was kept away from to body 1, and third staple bolt 18 and fourth staple bolt 19 set up with first staple bolt 2 and second staple bolt 3 perpendicularly, the internal diameter after third staple bolt 18 and the closure of fourth staple bolt 19 and the external diameter looks adaptation of body 1, all set up two second screw through-holes that the position is the same on the pterygoid lamina of third staple bolt 18 and fourth staple bolt 19, second screw through-hole female connection has second set screw 21, share the bearing by the second fixture that forms between third staple bolt 18 and the fourth staple bolt 19 to body 1, and second fixture sets up with first fixture is perpendicular, make the effort that the antidetonation support formed body 1 more even, the fastness of antidetonation support has further been improved.

The outer walls of the hoop plates of the third hoop 18 and the fourth hoop 19 are both fixedly provided with a second fixed block 20, one side of the bottom of the fixed transverse plate 12, which is far away from the hoop side plate 14, is fixedly connected with a second telescopic block 26, the bottom of the second telescopic block 26 is provided with two third mounting notches which are distributed in a mirror image manner, a second connecting block 30 is connected in the third mounting notches in a sliding manner, a plurality of third compression springs 28 which are distributed equidistantly are fixedly connected between the top of the second connecting block 30 and the top of the third mounting notches, the bottom of the second connecting block 30 is fixedly connected with a third supporting rod 17, the bottom of the third supporting rod 17 is fixedly connected with the top of the second fixed block 20 adjacent to the third supporting rod 17, a direct anti-seismic mechanism is formed between the second clamping mechanism and the fixed transverse plate 12 through the third supporting rod 17, the third compression spring 28 elastically supports the pipe body 1, and further ensures that the pipe body 1 cannot fall off or shake, thereby improving the firmness of the whole anti-seismic support.

The third support rod 17 and the first main support rod 5 are horizontally arranged, and the third support rod 17 forms longitudinal anti-seismic force on the pipe body 1, so that the firmness of the whole anti-seismic support is improved.

It is worth mentioning, refer to fig. 5, all fixedly on the hoop board inner wall of first staple bolt 2, second staple bolt 3, third staple bolt 18 and fourth staple bolt 19 be provided with antidetonation gasket 7, by antidetonation gasket 7 and body 1 direct contact, avoided causing the damage to body 1 at antidetonation in-process staple bolt, further improved the life of antidetonation support.

The working principle is as follows: when the anti-seismic support is used, the pipe body 1 is clamped and fixed by closing the first hoop 2 and the second hoop 3, the first hoop 2 and the second hoop 3 are fixedly connected by the first fixing screws 4, the stability of clamping the pipe body 1 is improved, the fixing vertical plate 9 is further firmly fixed on the mounting surface by the first fixing screws 10, when earthquake and other vibration happen, the first compression springs 22 between the first main support rod 5 and the second main support rod 6 resist the earthquake elastically, the damage of the anti-seismic support caused by rigid earthquake resistance is avoided, and the firmness of the anti-seismic support is further improved.

The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.

Claims

1. An anti-seismic support with a firm structure comprises a pipe body (1), and is characterized in that a first hoop (2) and a second hoop (3) are arranged on the outer wall of the pipe body (1), the first hoop (2) is positioned at the bottom of the outer wall of the pipe body (1), the second hoop (3) is positioned at the top of the outer wall of the pipe body (1), the inner diameter of the closed first hoop (2) and the closed second hoop (3) is matched with the outer diameter of the pipe body (1), two first threaded through holes with the same position are respectively formed in wing plates of the first hoop (2) and the second hoop (3), a first fixing screw (4) is connected in the first threaded through holes in a threaded manner, a first main support rod (5) is fixedly connected to a hoop plate of the second hoop (3) far away from the pipe body (1), a first mounting notch is formed in the top of the first main support rod (5), a second main supporting rod (6) is slidably mounted in the first mounting groove, a plurality of first compression springs (22) distributed at equal intervals are fixedly connected to the bottom of the mounting groove and the top of the second main supporting rod (6), a fixed vertical plate (9) is arranged at the top of the second main supporting rod (6), first connecting rods (8) are fixedly connected between the top of the second main supporting rod (6) and the same port of the bottom of the fixed vertical plate (9), and a plurality of first fixing screws (10) distributed at equal intervals are arranged on the fixed vertical plate (9).

2. The structurally firm anti-seismic support according to claim 1, characterized in that a fixing transverse plate (12) which is level with a fixing vertical plate (9) is arranged at the top of the second main supporting rod (6), a plurality of second fixing screws (16) which are distributed at equal intervals are arranged on the fixing transverse plate (12), a first clamping groove (23) is formed in the center of the bottom of the fixing vertical plate (9), a second clamping groove (24) which is matched with the first clamping groove (23) is formed in the top of the fixing transverse plate (12), and the fixing vertical plate (9) is clamped with the fixing transverse plate (12).

3. The structurally firm anti-seismic support according to claim 2, characterized in that one side of the second hoop (3) is fixedly connected with a hoop side plate (14), one end of the hoop side plate (14) far away from the pipe body (1) is fixedly connected with a first fixed block (15), one side of the bottom of the fixed transverse plate (12) close to the hoop side plate (14) is fixedly connected with a first telescopic block (25), the bottom of the first telescopic block (25) is provided with a second installation notch, a first connecting block (29) is slidably installed in the second installation notch, a plurality of second compression springs (27) distributed equidistantly are fixedly connected between the top of the first connecting block (29) and the top of the second installation notch, the bottom of the first connecting block (29) is fixedly connected with a second supporting rod (13), and the bottom of the second supporting rod (13) is fixedly connected with the top of the first fixed block (15), and the second support rod (13) and the fixed transverse plate (12) are obliquely arranged.

4. A structurally sound anti-seismic support according to claim 3, characterized in that the second connecting rods (11) are fixedly connected to both ends of one side of the fixed riser (9) close to the hoop side plates (14), and the other ends of the second connecting rods (11) far from the fixed riser (9) are fixedly connected to one side of the fixed transverse plate (12) close to the hoop side plates (14).

5. The anti-seismic support with the firm structure is characterized in that a third hoop (18) and a fourth hoop (19) are arranged on one side, away from the hoop side plate (14), of the pipe body (1), the third hoop (18) and the fourth hoop (19) are perpendicular to the first hoop (2) and the second hoop (3), the inner diameter of the closed third hoop (18) and the closed fourth hoop (19) is matched with the outer diameter of the pipe body (1), two second threaded through holes with the same position are formed in wing plates of the third hoop (18) and the fourth hoop (19), and a second fixing screw (21) is connected to the second threaded through holes in a threaded connection mode.

6. A structurally sound anti-seismic bracket according to claim 5, characterized in that the outer walls of the hoop plates of the third and fourth hoops (18, 19) are fixedly provided with second fixing blocks (20), a second expansion block (26) is fixedly connected with one side of the bottom of the fixed transverse plate (12) far away from the hoop side plate (14), the bottom of the second telescopic block (26) is provided with two third mounting notches which are distributed in a mirror image manner, a second connecting block (30) is connected in the third mounting notch in a sliding manner, a plurality of third compression springs (28) which are distributed at equal intervals are fixedly connected between the top of the second connecting block (30) and the top of the third mounting notch, the bottom of the second connecting block (30) is fixedly connected with a third supporting rod (17), the bottom of the third supporting rod (17) is fixedly connected with the top of the adjacent second fixing block (20).

7. A structurally sound seismic brace according to claim 6, characterised in that the third support bar (17) is arranged horizontally with the first main support bar (5).

8. A structurally sound anti-seismic support according to claim 7, characterized in that anti-seismic gaskets (7) are fixedly arranged on the inner walls of the hoop plates of the first hoop (2), the second hoop (3), the third hoop (18) and the fourth hoop (19).