CN215258577U - Air cleaner's support base - Google Patents

Abstract

The application relates to a supporting base of an air filter, which comprises a supporting plate and an outer tube, wherein the outer tube is vertically arranged below the supporting plate, a roller is connected to the inner vertical sliding part of the outer tube, and a driving wheel is arranged below the supporting plate and drives the roller to slide out of the inner part of the outer tube. This application has the process of sparingly operating personnel transport air cleaner to the effect that operating personnel operated is convenient for.

Description

Air cleaner's support base

Technical Field

The application relates to the field of air purification, in particular to a supporting base of an air filter.

Background

With the continuous development of economy, the continuous promotion of industrialization and urbanization, the air quality of cities gradually deteriorates in recent years, the content of dust and other pollutants in the air exceeds the standard, the haze of the cities is increased gradually, and the physical health of residents is threatened.

At present, an air filter is generally used indoors to filter outside air, so that purified and filtered air is discharged indoors, and the cleanness degree of the indoor air is guaranteed.

In view of the above-mentioned related art, the inventor believes that when the air filter is used, the air filter is generally supported by the support base, but when the air filter is moved, the air filter needs to be moved to the flat car, and then moved to the support base from the flat car after being moved to the proper position, so that the operation of the operator is complicated and the workload is large.

SUMMERY OF THE UTILITY MODEL

In order to save the process that operating personnel carried air cleaner to be convenient for operating personnel operates, this application provides an air cleaner's support base.

The application provides a support base of air cleaner adopts following technical scheme:

the utility model provides an air cleaner's support base, is including the backup pad, still including being located the outer tube of the vertical setting in backup pad below, the vertical sliding connection in inside that is located the outer tube has the gyro wheel, the below of backup pad is provided with the drive the gyro wheel certainly the first drive structure of the inside roll-off of outer tube.

Through adopting above-mentioned technical scheme, need not remove at the filter at ordinary times, can withdraw the inside at the outer tube with the gyro wheel, make the diapire and the ground contact of outer tube, thereby will support the base and support subaerial, when needs remove the filter, drive its inside roll-off from the outer tube with the gyro wheel through first drive structure, make the bottom of pulley be less than the bottom of outer tube, thereby make pulley and ground contact, and then the pulley can drive the filter and remove, save operating personnel's transport air cleaner's process, thereby the operating personnel of being convenient for operates.

Optionally, the first driving structure is located including the cam of gyro wheel top, the cam with the outer tube rotates to be connected, just the rotation axis level of cam sets up, the cam with the gyro wheel rolls and links to each other, works as when the major axis of cam is vertical, the gyro wheel certainly the diapire of outer tube stretches out, works as when the minor axis of cam is vertical, the gyro wheel is located the inside of outer tube, one side of cam is provided with the drive cam pivoted second driving structure.

By adopting the technical scheme, the cam is driven to rotate through the second driving structure, so that when the long shaft of the cam is vertically arranged, the bottom end of the roller extends out of the bottom end of the outer pipe, and the roller is contacted with the ground, so that the cam can drive the filter to move; when the second driving piece drives the cam to rotate and is the vertical setting of short axis, the outer tube is descended by gravity to withdraw the inside of outer tube with the gyro wheel, make the bottom and the ground contact of outer tube, thereby restricted the removal of filter.

Optionally, the second drive structure including with the coaxial fixed connection's of cam first pivot, fixed cover is equipped with first bevel gear in the first pivot, one side meshing of first bevel gear is connected with second bevel gear, second bevel gear's rotation center fixedly connected with second pivot, be provided with the drive in the second pivot pivoted first driving piece.

Through adopting above-mentioned technical scheme, drive the second pivot through first driving piece and rotate, and then the second pivot drives second bevel gear and rotates, and second bevel gear drives the first bevel gear rather than the meshing connection and rotates, and then the first bevel gear of pivoted can drive first pivot and rotate for first pivot drives the cam and rotates.

Optionally, first drive structure is including being located backup pad below fixed connection's interior pole, the coaxial sliding connection of outer tube is in the outside of interior pole, the coaxial rotation in below of interior pole is connected with the lead screw, one side of lead screw is provided with the drive lead screw pivoted third drive structure, threaded connection has solid fixed ring on the pole body of lead screw, gu fixed ring with outer tube fixed connection.

By adopting the technical scheme, the screw rod is driven to rotate through the third driving structure, so that the fixing ring in threaded connection with the screw rod can move up and down along the axis direction of the screw rod, and the outer tube fixedly connected with the fixing ring is driven to move up and down; make when the lead screw rotates, can drive the outer tube and reciprocate, and then adjust the high relation between outer tube and the gyro wheel, when the outer tube rebound, expose the gyro wheel for gyro wheel and ground contact drive the filter through the gyro wheel and remove, move down when the outer tube, withdraw the inside of outer tube with the gyro wheel, make the diapire and the ground contact of outer tube, make the filter fixed with ground.

Optionally, the third driving structure comprises a first chain wheel fixedly sleeved outside the screw rod, a second chain wheel is rotatably connected below the supporting plate, the axis of the first chain wheel is parallel to the axis of the second chain wheel, a second driving piece for driving the second chain wheel to rotate is fixedly arranged below the second chain wheel, a first chain is sleeved on the outer layers of the first chain wheel and the second chain wheel, and the first chain is meshed with the first chain wheel and the second chain wheel respectively.

Through adopting above-mentioned technical scheme, drive the second sprocket through the second driving piece and rotate, and the pivoted second sprocket drives the first chain of being connected rather than the meshing and rotates, and first chain drives the first sprocket of being connected rather than the meshing and rotates, and then first sprocket can drive the lead screw and rotate.

Optionally, the inner side wall of the outer tube is vertically provided with a rotation stopping groove, a rotation stopping block is fixedly connected to the rod body of the inner rod at a position corresponding to the rotation stopping groove, and the rotation stopping block extends into the rotation stopping groove and is in relative sliding connection with the rotation stopping groove.

Through adopting above-mentioned technical scheme, through ending the piece and starting vertically in the inside of groove that splines, and end a piece and interior pole fixed connection that splines to it can only reciprocate to have restricted the outer tube through ending the piece that splines, can not rotate, thereby has reduced because the friction between lead screw and the fixed cover drives the outer tube and the synchronous pivoted condition that carries out of lead screw.

Optionally, a spring plate is horizontally arranged above the supporting plate, and a plurality of elastic members are arranged between the spring plate and the supporting plate.

Through adopting above-mentioned technical scheme, through spring board and the elastic component that is located spring board below for when ground produces the vibration, can absorb vibration through the elastic component, thereby reduce the influence that vibration produced to the filter.

Optionally, one side fixedly connected with of backup pad increases the subassembly, increase the subassembly including with the diaphragm that increases that the backup pad level set up, it increases a plurality of risers that increase to increase the below fixedly connected with of diaphragm.

Through adopting above-mentioned technical scheme, support increasing the shrouding through increasing the riser, and support the shrouding and support the air intake pump of filter to reduced because the air intake pump lacks the cracked condition that the support produced the long-time gravity production of being connected of air intake pump and rose box position department.

In summary, the present application includes at least one of the following beneficial technical effects:

1. at ordinary times when the filter need not remove, can withdraw the inside at the outer tube with the gyro wheel, make the diapire and the ground contact of outer tube, thereby will support the base and support subaerial, when needs remove the filter, drive the pulley from the inside roll-off of outer tube through first drive structure, make the bottom of pulley be less than the bottom of outer tube, thereby make pulley and ground contact, and then make the pulley can drive the filter and remove, save operating personnel's transport air cleaner's process, thereby the operating personnel of being convenient for operates.

2. The cam is driven to rotate through the second driving structure, so that when the long shaft of the cam is vertically arranged, the bottom end of the roller extends out of the bottom end of the outer pipe, and the roller is contacted with the ground, so that the cam can drive the filter to move; when the second driving piece drives the cam to rotate and is the vertical setting of short axis, the outer tube is descended by gravity to withdraw the inside of outer tube with the gyro wheel, make the bottom and the ground contact of outer tube, thereby restricted the removal of filter.

3. Drive the lead screw through third drive structure and rotate, make solid fixed ring with lead screw threaded connection can reciprocate along the axis direction of lead screw, and reciprocate through the outer tube with solid fixed ring fixed connection, make when the lead screw rotates, can drive the outer tube and reciprocate, and then adjust the altitude relation between outer tube and the gyro wheel, when the outer tube rebound, expose the gyro wheel, make gyro wheel and ground contact, it removes to drive the filter through the gyro wheel, when the outer tube rebound, withdraw the inside of outer tube with the gyro wheel, make the diapire and the ground contact of outer tube, make the filter fixed with ground.

Drawings

Fig. 1 is a schematic view of the overall structure of a support base of an air filter in embodiment 1 of the present application;

fig. 2 is a schematic view of a driving structure of a support base of an air filter in embodiment 1 of the present application;

FIG. 3 is an enlarged view of portion A of FIG. 2;

FIG. 4 is a schematic view showing the overall structure of a support base of an air cleaner according to embodiment 2 of the present application;

FIG. 5 is a schematic view of the internal structure of an outer tube of a support base of an air filter according to embodiment 2 of the present application;

FIG. 6 is a schematic view of a driving structure of a supporting base of an air cleaner in embodiment 2 of the present application;

fig. 7 is an enlarged view of a portion B in fig. 6.

Description of reference numerals: 1. a filter body; 11. a filter box; 12. an air intake pump; 2. a support plate; 21. a spring plate; 22. a spring; 3. an outer tube; 31. a sliding plate; 32. a roller; 33. a first connecting rod; 34. a second connecting rod; 35. a connecting plate; 36. avoiding holes; 37. a rotation stopping groove; 4. a drive structure; 41. a cam; 42. a first rotating shaft; 43. a first bevel gear; 44. a second rotating shaft; 45. a second bevel gear; 46. a first gear; 47. a second gear; 48. a first rotating electric machine; 5. a heightening component; 51. heightening the transverse plate; 52. heightening a vertical plate; 6. an inner rod; 61. fixing a sleeve; 611. a rotation stopping block; 62. a lead screw; 63. a first sprocket; 64. a fixing ring; 641. fixing the rod; 7. a support frame; 71. supporting the transverse plate; 72. a support vertical plate; 8. a drive shaft; 81. a second rotating electric machine; 82. a second sprocket; 83. a third sprocket; 84. a first sprocket set; 85. a second sprocket set; 86. a first chain; 87. and a second chain.

Detailed Description

The present application is described in further detail below with reference to figures 1-7.

The embodiment of the application discloses air cleaner's support base.

Example 1

Referring to fig. 1 and 2, the supporting base of the air filter comprises a filter body 1, a supporting plate 2 horizontally arranged below the filter body 1, outer tubes 3 vertically arranged at four corners below the supporting plate 2 respectively, and a top wall of each outer tube 3 fixedly connected with the supporting plate 2. The outer tube 3 is a rectangular hollow structure.

Referring to fig. 1 and 3, a sliding plate 31 is vertically and slidably connected inside the outer tube 3, rollers 32 are fixedly arranged below the sliding plate 31, and a driving mechanism 4 for driving the sliding plate 31 to move up and down is arranged above the supporting plate 2.

The filter body 1 includes a filter box 11, an air intake pump 12 is fixedly connected to one side of the filter box 11, and external air is pumped into the filter box 11 through the air intake pump 12 for filtering.

Referring to fig. 1 and 2, two first connecting rods 33 and two second connecting rods 34 are respectively arranged on the side wall of the outer tube 3, the axes of the two first connecting rods 33 are arranged in parallel, the axes of the two second connecting rods 34 are arranged in parallel, the axes of the first connecting rods 33 are perpendicular to the axes of the second connecting rods 34, and the first connecting rods 33 and the second connecting rods 34 are sequentially connected end to end along the circumferential direction to form a frame structure. The arrangement direction along the first connecting rod 33 is a longitudinal direction. Connecting plates 35 are horizontally arranged on the two opposite second connecting rods 34, and two ends of each connecting plate 35 are respectively fixed with the first connecting rods 33.

Referring to fig. 2 and 3, the driving structure 4 includes a cam 41, a rotation axis of the cam 41 is disposed along a length direction, the cam 41 is connected to the sliding plate 31 in a rolling manner, a first rotation shaft 42 is fixedly connected along a rotation center of the cam 41, the first rotation shaft 42 is horizontally disposed and has an axis disposed along the length direction, the first rotation shaft 42 extends from a side wall of the outer tube 3 and is connected to the side wall in a relatively rotating manner, and two ends of the first rotation shaft 42 respectively fixedly connect two cams 41 opposite along the length direction.

Referring to fig. 1 and 2, a first bevel gear 43 is fixedly fitted to a position on the shaft of the first shaft 42 opposite to the connecting plate 35, and the first bevel gear 43 is disposed coaxially with the first shaft 42. A second rotating shaft 44 is rotatably connected below the connecting plate 35, the second rotating shaft 44 is arranged along the width direction, two ends of the second rotating shaft 44 are respectively and coaxially provided with a second bevel gear 45, the second bevel gear 45 is fixedly connected with the second rotating shaft 44, and the first bevel gear 43 is in opposite meshing connection with the second bevel gear 45.

A first gear 46 is coaxially arranged on the shaft of the second rotating shaft 44, the first gear 46 is fixedly connected with the second rotating shaft 44, one side of the first gear 46 is meshed with a second gear 47, the second gear 47 is rotatably connected with the connecting plate 35, a first rotating motor 48 is fixedly connected with the rotating center of the second gear 47, and the first rotating motor 48 is horizontally arranged and fixedly connected with the connecting plate 35. Thereby, the first rotating motor 48 drives the second gear 47 to rotate, and the second gear 47 drives the first gear 46 engaged with the second gear to rotate, so as to drive the second rotating shaft 44 to rotate, so that the second rotating shaft 44 drives the first rotating shaft 42 to rotate through the first bevel gear 43 and the second bevel gear 45 engaged with each other, and finally the driving cam 41 rotates.

Referring to fig. 2 and 3, when the long axis of the cam 41 is vertically arranged, the cam 41 drives the sliding plate 31 to move downwards, so that the sliding plate 31 drives the roller 32 to move downwards, and the roller 32 extends out of the inner part of the outer tube 3; when the short axis of the cam 41 is vertically disposed, the entire weight presses down the outer tube 3, so that the outer tube 3 descends, and the roller 32 is completely located inside the outer tube 3, so that the support plate 2 is supported by the outer tube 3.

Referring to fig. 1 and 4, the side is provided with the height increasing subassembly 5, and the height increasing subassembly 5 is located the vertical three risers 52 that increase that are provided with of below that increases the diaphragm 51 including the height diaphragm 51 that the level set up, increases the vertical setting of riser 52. The top that increases the riser 52 with increase diaphragm 51 fixed connection, and increase fixed connection between the bottom of riser 52 and the backup pad 2 to increase diaphragm 51 and support through increasing riser 52, and then support air intake pump 12 through increasing subassembly 5.

The implementation principle of the embodiment 1 is as follows: by starting the first rotating motor 48, the first rotating motor 48 drives the second gear 47 to rotate, so that the second gear 47 drives the first gear 46 engaged with the second gear to rotate, and then the first gear 46 drives the second rotating shaft 44 fixedly connected with the first gear to rotate, and the second rotating shaft 44 can drive the second bevel gear 45 fixedly connected with the second rotating shaft to rotate, so that the second bevel gear 45 drives the first bevel gear 43 to rotate, and then the first bevel gear 43 drives the first rotating shaft 42 to rotate, so that the first rotating shaft 42 drives the cam 41 to rotate, and the cam 41 drives the sliding plate 31 to move up and down.

When the long axis of the cam 41 is vertically arranged, the cam 41 drives the sliding plate 31 to move downwards, so that the sliding plate 31 drives the roller 32 to extend out of the inner part of the outer tube 3, the supporting plate 2 is supported by the roller 32, and the supporting plate 2 can be driven by the roller 32 to move.

When the long axis of the cam 41 is horizontally disposed, the outer tube 3 is dropped by gravity, and the roller 32 is retracted into the outer tube 3, so that the support plate 2 is supported by the outer tube 3, and the support plate 2 cannot be moved.

Example 2

Referring to fig. 4 and 5, the present embodiment is different from embodiment 1 in that a spring plate 21 is horizontally disposed above the support plate 2, a plurality of springs 22 are fixedly connected to the bottom end of the spring plate 21, the springs 22 are vertically disposed, one end of each spring 22 is fixedly connected to the spring plate 21, and the other end of each spring plate 21 is fixedly connected to the support plate 2. The spring plate 21 is damped by the springs 22, thereby reducing the effect of vibration on the filter body 1.

An inner rod 6 is vertically arranged at four corners below the supporting plate 2, the inner rod 6 is of a cylindrical structure, and the top end of the inner rod 6 is fixedly connected with the supporting plate 2. The outer tube 3 is sleeved on the outer side of the inner rod 6, the outer tube 3 is a hollow cylindrical shell, and the inner rod 6 is connected with the outer tube 3 in a sliding mode.

The outer side of the bottom end of the inner rod 6 is fixedly sleeved with a fixed sleeve 61, and the fixed sleeve 61 and the inner rod 6 are coaxially arranged. The screw 62 is coaxially arranged below the fixed sleeve 61, the top end of the screw 62 is rotatably connected with the fixed sleeve 61, and the bottom end of the screw 62 is rotatably connected with the sliding plate 31.

A first chain wheel 63 is fixedly connected to the body of the lead screw 62, and the first chain wheel 63 and the lead screw 62 are coaxially arranged. The central position fixedly connected with carriage 7 that is located the lower surface of backup pad 2, carriage 7 is including the support diaphragm 71 that the level set up, is located the both ends of support diaphragm 71 vertical fixedly connected with support riser 72 respectively, support riser 72's top and backup pad 2 fixed connection.

Referring to fig. 6 and 7, a driving shaft 8 is rotatably connected to the supporting cross plate 71, and the driving shaft 8 is vertically disposed to penetrate and relatively rotatably connect the supporting cross plate 71. A second rotating motor 81 is fixedly connected to the lower surface of the supporting horizontal plate 71 at a position corresponding to the driving shaft 8, and a motor shaft of the second rotating motor 81 is coaxial and fixedly connected with the driving shaft 8.

The side wall of the driving shaft 8 is respectively and fixedly connected with a second chain wheel 82 positioned above and a third chain wheel 83 positioned below the second chain wheel 82, and the driving shaft 8 is driven to rotate by a second rotating motor 81, so that the second chain wheel 82 and the third chain wheel 83 are synchronously driven to rotate.

The two first sprockets 63 located at the four lower corners of the support plate 2 and along the diagonal direction of the support plate 2 are grouped, and the four first sprockets 63 are divided into a first sprocket group 84 and a second sprocket group 85 according to the diagonal connecting direction. First sprocket 63 of first sprocket group 84 is relative with second sprocket 82 in the direction of height, and the outside meshing cover of first sprocket 63 of first sprocket group 84 is equipped with first chain 86, and first chain 86 meshes with second sprocket 82 relatively for pivoted second sprocket 82 can drive first chain 86 and rotate, and then first chain 86 can drive first sprocket 63 of first sprocket group 84 and rotate.

The first chain wheel 63 of the second chain wheel set 85 is opposite to the third chain wheel 83 in the height direction, the second chain 87 is meshed with the outer side of the first chain wheel 63 of the second chain wheel set 85 in a sleeved mode, the second chain 87 is meshed with the third chain wheel 83 in a relative mode, the third chain wheel 83 can drive the second chain 87 to rotate, and then the first chain wheel 63 of the second chain wheel set 85 can be driven by the second chain 87 to rotate.

Referring to fig. 5 and 6, the avoidance holes 36 are formed in the side wall of the outer tube 3 at positions corresponding to the first chain 86 and the second chain 87, the side wall of the outer shell is penetrated through the avoidance holes 36, and the first chain 86 and the second chain 87 can extend out of the inner portion of the outer tube 3 and move up and down through the avoidance holes 36.

A fixing ring 64 is coaxially and threadedly connected to the outer side of the screw 62, the fixing ring 64 is fixed to the outer tube 3 by a horizontally disposed fixing rod 641, one end of the fixing rod 641 is fixedly connected to the fixing ring 64, and the other end of the fixing rod 641 is fixedly connected to the outer tube 3. Thereby, the first chain wheel 63 drives the screw 62 to rotate, and further drives the fixing ring 64 to move along the axis direction of the screw 62, and drives the outer tube 3 to move along the axis direction.

The inner side wall of the outer tube 3 is vertically provided with a rotation stopping groove 37, the outer side of the fixing sleeve 61 is fixedly connected with a rotation stopping block 611 relative to the rotation stopping groove 37, and the rotation stopping block 611 extends into the rotation stopping groove 37 and is in relative sliding connection, so that the outer tube 3 can only move up and down and cannot rotate through the relative matching of the rotation stopping block 611 and the rotation stopping groove 37.

The implementation principle of the embodiment 2 is as follows: drive shaft 8 through second rotation motor 81 and rotate, make drive shaft 8 drive second sprocket 82 and third sprocket 83 rotate, and second sprocket 82 drives the inside first sprocket 63 of first sprocket group 84 and rotates, third sprocket 83 drives the inside first sprocket 64 of second sprocket group 85 and rotates, thereby first sprocket 63 drives and rotates rather than fixed connection's lead screw 62, and then pivoted lead screw 62 drives solid fixed ring 64 and reciprocates along its axis direction, and then drive and gu the fixed outer tube 3 of fixed ring 64 reciprocates.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (8)

1. The utility model provides an air cleaner's support base, is including backup pad (2), its characterized in that: still including being located outer tube (3) of the vertical setting in backup pad (2) below, the vertical sliding connection in inside that is located outer tube (3) has gyro wheel (32), the below of backup pad (2) is provided with the drive gyro wheel (32) certainly the first drive structure of the inside roll-off of outer tube (3).

2. A support base for an air filter according to claim 1, wherein: first drive structure is including being located cam (41) of gyro wheel (32) top, cam (41) with outer tube (3) rotate to be connected, just the axis of rotation level of cam (41) sets up, cam (41) with gyro wheel (32) roll and link to each other, work as when the vertical setting of major axis of cam (41), gyro wheel (32) certainly the diapire of outer tube (3) stretches out, works as when the vertical setting of minor axis of cam (41), gyro wheel (32) are located the inside of outer tube (3), one side of cam (41) is provided with the drive cam (41) pivoted second drive structure.

3. A support base for an air filter according to claim 2, wherein: the second drive structure including with cam (41) coaxial fixed connection's first pivot (42), fixed cover is equipped with first bevel gear (43) on first pivot (42), one side meshing of first bevel gear (43) is connected with second bevel gear (45), the rotation center fixedly connected with second pivot (44) of second bevel gear (45), be provided with the drive on second pivot (44) pivoted first driving piece.

4. A support base for an air filter according to claim 1, wherein: first drive structure is including being located interior pole (6) of backup pad (2) below fixed connection, outer tube (3) coaxial sliding connection be in the outside of interior pole (6), the below coaxial rotation of interior pole (6) is connected with lead screw (62), one side of lead screw (62) is provided with the drive lead screw (62) pivoted third drive structure, threaded connection has solid fixed ring (64) on the pole body of lead screw (62), gu fixed ring (64) with outer tube (3) fixed connection.

5. A support base for an air filter, as defined in claim 4, wherein: the third driving structure comprises a first chain wheel (63) fixedly sleeved outside the lead screw (62), a second chain wheel (82) is connected to the lower portion of the supporting plate (2) in a rotating mode, the axis of the first chain wheel (63) is parallel to the axis of the second chain wheel (82), a second driving piece for driving the second chain wheel (82) to rotate is fixedly arranged below the second chain wheel (82), a first chain (86) is sleeved on the outer layer of the first chain wheel (63) and the outer layer of the second chain wheel (82), and the first chain (86) is meshed with the first chain wheel (63) and the second chain wheel (82) respectively.

6. A support base for an air filter, as defined in claim 4, wherein: the inner side wall of the outer pipe (3) is vertically provided with a rotation stopping groove (37), a rotation stopping block (611) is fixedly connected to the shaft body of the inner rod (6) relative to the rotation stopping groove (37), and the rotation stopping block (611) extends into the rotation stopping groove (37) and is in relative sliding connection.

7. A support base for an air filter according to claim 1, wherein: a spring plate (21) is horizontally arranged above the supporting plate (2), and a plurality of elastic pieces are arranged between the spring plate (21) and the supporting plate (2).

8. A support base for an air filter according to claim 1, wherein: one side fixedly connected with of backup pad (2) increases subassembly (5), increase subassembly (5) including with backup pad (2) level sets up increases diaphragm (51), the below fixedly connected with that increases diaphragm (51) a plurality of risers (52) that increase.

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