CN112230141A

CN112230141A - Narrow and small space running gear of wave recorder for detection of wind driven generator

Info

Publication number: CN112230141A
Application number: CN202010886188.XA
Authority: CN
Inventors: 杨河; 王苹; 沈华慧
Original assignee: Nanjing Ruiyi Electronic Technology Co Ltd
Current assignee: Nanjing Ruiyi Electronic Technology Co Ltd
Priority date: 2020-08-28
Filing date: 2020-08-28
Publication date: 2021-01-15

Abstract

The invention belongs to the technical field of wave recorders, and particularly relates to a narrow-space traveling device of a wave recorder for detecting a wind driven generator. This narrow and small space running gear of wave recorder is used in aerogenerator detection, anti-skidding device that has the gyro wheel through the lower surface mounting that sets up at the wave recorder, the rolling friction of utilizing gyro wheel and ground replaces the sliding friction of wave recorder body lower surface and ground, and then reduce coefficient of friction, the removal of the wave recorder body of being convenient for, and simultaneously, utilize to support sealed lid through the universal wheel at the lower extreme of sealed lid, the rolling friction of utilizing universal wheel and ground replaces the sliding friction of sealed lid lower surface and ground, and then reduce coefficient of friction, the removal of the sealed lid of being convenient for, and support mutually through sealed lid and wave recorder body, it moves together to drive the wave recorder through the sealed lid of handle pulling, thereby make and have the characteristics that the wave recorder of being convenient for removed in narrow and small space.

Description

Narrow and small space running gear of wave recorder for detection of wind driven generator

Technical Field

The invention relates to the technical field of wave recorders, in particular to a narrow-space traveling device of a wave recorder for detecting a wind driven generator.

Background

The wind power generator is an electric power device which converts wind energy into mechanical work, and the mechanical work drives a rotor to rotate so as to finally output alternating current. The wind power generator generally comprises components such as a wind wheel, a generator (including a device), a direction regulator (empennage), a tower, a speed-limiting safety mechanism, an energy storage device and the like; the wind driven generator has simple working principle, the wind wheel rotates under the action of wind force, the kinetic energy of the wind is converted into mechanical energy of a wind wheel shaft, and the generator rotates under the drive of the wind wheel shaft to generate electricity. In a broad sense, wind energy is also solar energy, so that the wind driven generator is a heat energy utilization generator which takes the sun as a heat source and takes the atmosphere as a working medium;

maintenance and repair of the wind driven generator maintains the energy storage battery according to the phenomenon of the generator. The storage battery is scientifically and reasonably used and maintained, the use efficiency is fully exerted, the service life is prolonged, and the method is a technical key for using the wind driven generator;

aerogenerator needs to detect aerogenerator's motor through the record ripples appearance in the maintenance process, and because aerogenerator's inner space is narrow and small, the record ripples appearance is not convenient for take, simultaneously because the record ripples appearance has certain gravity, is not convenient for carry, therefore needs a aerogenerator to detect with the narrow and small space running gear of record ripples appearance.

Disclosure of Invention

Based on the technical problem that the existing wave recorder is inconvenient to carry in a narrow space in a wind driven generator, the invention provides a narrow-space traveling device of the wave recorder for detecting the wind driven generator.

The narrow space traveling device of the wave recorder for detecting the wind driven generator comprises a wave recorder body, wherein a sealing cover is hinged to the lower end of the right side wall of the wave recorder body, the side wall of the sealing cover is matched and aligned with the side wall of the wave recorder body, the left side wall of the sealing cover is connected with the right side wall of the wave recorder body in a sliding mode, an anti-skidding device is installed at the lower end of the wave recorder body, the wave recorder is fixed and prevented from skidding when the anti-skidding device is used, the anti-skidding device comprises a supporting column, a traveling device is installed on the surface of the sealing cover, friction between the wave recorder and the ground is reduced through the traveling device, and the traveling device comprises a threaded rod.

Preferably, a first bearing is installed at the lower table left end of oscillograph body, the upper end of the inside wall fixedly connected with support column of first bearing, the lower surface sliding connection of support column has the connecting block, the lower fixed surface of support column is connected with the gag lever post, the spacing groove has been seted up to the upper surface of connecting block.

Through above-mentioned technical scheme, utilize and install first bearing at the lower table left end of oscillograph body, through first bearing joint support post and oscillograph body to the level of the support post of being convenient for rotates.

Preferably, the inner wall sliding connection of spacing groove has the gag lever post, the equal fixedly connected with spring of both sides wall of gag lever post, two the terminal two inside walls of fixedly connected with spacing groove respectively of spring, the equal fixedly connected with dead lever in lower surface both ends of connecting block.

Through above-mentioned technical scheme, utilize the equal fixedly connected with spring of both sides wall of gag lever post, consolidate the being connected of gag lever post and spacing groove through the spring at the both ends direction of spacing groove to be convenient for prevent that connecting block and support column from taking place the swing when the walking.

Preferably, two the equal fixedly connected with sucking disc of the lateral wall lower extreme that backs on the back of the body of dead lever, two the fixed orifices have all been seted up to the lateral wall of dead lever, two the equal adaptation in surface of fixed orifices aligns, two the inside wall of fixed orifices is all fixed the grafting has same fixed axle.

Through above-mentioned technical scheme, utilize at the equal fixedly connected with sucking disc of dead lever lateral wall lower extreme back of the body mutually, through record ripples appearance body during operation, the sucking disc bonds with ground to the firm of record ripples appearance body during operation.

Preferably, the surface mounting of fixed axle has the gyro wheel, the gyro wheel is located between two adjacent dead levers, the axis of gyro wheel and the axis of fixed axle are all on same straight line, the draw-in groove has all been seted up to the both sides wall of gyro wheel, the lateral wall of draw-in groove is the ring form.

Through the technical scheme, the surface of the fixing shaft is provided with the roller, and the roller is positioned between the two adjacent fixing rods, so that the recorder body is convenient to walk while the recorder body is supported by the roller.

Preferably, the inner wall fixedly connected with slipmat of draw-in groove, the lateral wall of slipmat is the ring form, the inner wall fixedly connected with pin of draw-in groove, the both ends of pin all with the inside wall fixed connection of draw-in groove, the pin is the ring array and distributes in the inside of draw-in groove.

Through above-mentioned technical scheme, utilize inner wall fixedly connected with slipmat and the pin at the draw-in groove, when carrying out the reinforcement through the pin to the draw-in groove inner wall, be convenient for increase the friction in the draw-in groove.

Preferably, a threaded hole is formed in the right end of the upper surface of the sealing cover, the lower end of the threaded hole is communicated with the lower portion of the sealing cover, a threaded rod is connected to the inner wall of the threaded hole in a threaded mode, a gasket is fixedly sleeved at the lower end of the threaded rod, and the upper surface of the gasket is in sliding connection with the lower surface of the sealing cover.

Through above-mentioned technical scheme, utilize the inner wall threaded connection of screw hole to have the threaded rod to be convenient for through rotatory threaded rod, and then the up-and-down operation of control threaded rod in the screw hole.

Preferably, the universal wheel is installed to the lower extreme of threaded rod, the universal wheel is located the below of sealed lid, the fixed rotary disk that has cup jointed in upper end of threaded rod, the lower surface of rotary disk and the upper surface sliding connection of sealed lid.

Through above-mentioned technical scheme, the fixed cover in upper end that utilizes the threaded rod has connect the rotary disk to be convenient for through the rotation of rotary disk control threaded rod.

Preferably, the upper surface of the rotating disc is provided with rotating grooves, the rotating grooves are distributed on the surface of the rotating disc in an annular array mode, the upper ends of the two threaded rods are provided with second bearings, and the upper ends of the two second bearings are fixedly connected with the same handle.

Through above-mentioned technical scheme, utilize the second bearing to connect handle and threaded rod to be convenient for avoid disturbing the handle when rotating the threaded rod.

Preferably, the display screen is installed to the left side wall of sealed lid, display screen and record appearance body electric connection, the last fixed surface of record appearance body is connected with the hasp and keeps silent, the last fixed surface of sealed lid is connected with hasp tongue seat, hasp keep silent and hasp tongue seat overlap joint.

Through above-mentioned technical scheme, utilize record ripples appearance body and sealed lid to carry out the overlap joint through hasp keeping silent and hasp tongue seat to when being convenient for record ripples appearance walking, fixed between record ripples appearance body and the sealed lid.

The beneficial effects of the invention are as follows:

1. have the antiskid of gyro wheel through the lower surface mounting who sets up at the record appearance, the rolling friction who utilizes gyro wheel and ground replaces the sliding friction of record appearance body lower surface and ground, and then reduce coefficient of friction, be convenient for the removal of record appearance body, and simultaneously, utilize the lower extreme at sealed lid to support through the universal wheel to sealed lid, the rolling friction who utilizes universal wheel and ground replaces the sliding friction of sealed lid lower surface and ground, and then reduce coefficient of friction, be convenient for the removal of sealed lid, and support mutually through sealed lid and record appearance body, it moves together to drive the record appearance through the sealed lid of handle pulling, thereby make to have the characteristics that the record appearance of being convenient for removed in narrow and small space.

2. Through the specification that sets up the universal wheel and the interior interval adaptation between two pin of draw-in groove, when the record ripples appearance uses, the record ripples appearance level is placed, the left side wall and the ground contact of record ripples appearance body, place with the same level of record ripples appearance body through the adjustment gyro wheel, expand sealed lid, and utilize the rotary disk on rotatory sealed lid surface, it descends to drive the threaded rod through the rotary disk, make the universal wheel lower extreme of threaded rod lower extreme stretch into in the draw-in groove, and support tightly with the gag lever post and the slipmat of draw-in groove inner wall, make the gyro wheel descend with connecting to open the removal, the sucking disc of dead lever lateral wall bonds with ground, and then carry out spacing fixed to the record ripples appearance body, thereby make to have the firm characteristics of the record ripples appearance use of.

3. Through setting up the lower extreme installation gag lever post at the support column, with the inside spacing groove sliding connection of gag lever post and connecting block, utilize the lower extreme of gag lever post and the lower extreme surface adaptation of spacing groove, make gag lever post and spacing groove when vertical direction joint of each other, the gag lever post can freely translate at the horizontal direction, and support tightly through setting up the spring at the inside wall both ends of spacing groove to the lateral wall of gag lever post, avoid the gag lever post too swing when the oscillograph walking, influence the walking, thereby make to have the characteristics of being convenient for to control antiskid and move.

Drawings

Fig. 1 is a schematic view of a narrow space traveling device of a wave recorder for wind driven generator detection, which is provided by the invention;

FIG. 2 is a perspective view of an anti-skid device of a narrow-space traveling device of a wave recorder for wind driven generator detection, which is provided by the invention;

FIG. 3 is a front sectional view of a connecting block structure of a narrow-space traveling device of a wave recorder for wind driven generator detection, which is provided by the invention;

FIG. 4 is a side sectional view of a connecting block structure of a narrow-space traveling device of a wave recorder for wind driven generator detection, which is provided by the invention;

FIG. 5 is a side sectional view of a roller structure of a narrow-space traveling device of a wave recorder for wind turbine detection, according to the present invention;

fig. 6 is a sectional view of a sealing cover structure of a narrow space traveling device of a wave recorder for wind driven generator detection provided by the invention.

In the figure: 1. a wave recorder body; 2. a sealing cover; 3. a support pillar; 4. a threaded rod; 5. a first bearing; 6. connecting blocks; 7. a limiting rod; 8. a limiting groove; 9. a spring; 10. fixing the rod; 11. a suction cup; 12. a fixing hole; 13. a fixed shaft; 14. a roller; 15. a card slot; 16. a non-slip mat; 17. a stop lever; 18. a threaded hole; 19. a gasket; 20. a universal wheel; 21. rotating the disc; 22. a rotating tank; 23. a second bearing; 24. a handle; 25. a display screen; 26. snapping the jaw; 27. a hasp tongue seat.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Referring to fig. 1-6, a narrow space traveling device of a wave recorder for wind turbine detection comprises a wave recorder body 1, a sealing cover 2 is hinged to the lower end of the right side wall of the wave recorder body 1, the side wall of the sealing cover 2 is matched and aligned with the side wall of the wave recorder body 1, the left side wall of the sealing cover 2 is connected with the right side wall of the wave recorder body 1 in a sliding mode, an anti-skid device is installed at the lower end of the wave recorder body 1 and used for fixing and preventing the wave recorder from skidding, the anti-skid device comprises a supporting column 3 and a traveling device is installed on the surface of the sealing cover 2, friction between the wave recorder and the ground is reduced through the traveling device, and the traveling device comprises a threaded rod 4;

further, a first bearing 5 is installed at the left end of the lower surface of the wave recorder body 1, the upper end of a support column 3 is fixedly connected to the inner side wall of the first bearing 5, a connecting block 6 is slidably connected to the lower surface of the support column 3, a limiting rod 7 is fixedly connected to the lower surface of the support column 3, and a limiting groove 8 is formed in the upper surface of the connecting block 6;

furthermore, the inner wall of the limiting groove 8 is slidably connected with a limiting rod 7, two side walls of the limiting rod 7 are fixedly connected with springs 9, the tail ends of the two springs 9 are fixedly connected with two inner side walls of the limiting groove 8 respectively, and two ends of the lower surface of the connecting block 6 are fixedly connected with fixing rods 10;

further, the lower ends of the opposite side walls of the two fixing rods 10 are fixedly connected with suckers 11, the side walls of the two fixing rods 10 are respectively provided with a fixing hole 12, the surfaces of the two fixing holes 12 are matched and aligned, and the inner side walls of the two fixing holes 12 are fixedly inserted with a same fixing shaft 13;

furthermore, the surface of the fixed shaft 13 is provided with a roller 14, the roller 14 is positioned between two adjacent fixed rods 10, the axes of the roller 14 and the fixed shaft 13 are all on the same straight line, the two side walls of the roller 14 are both provided with clamping grooves 15, and the side walls of the clamping grooves 15 are annular;

furthermore, the inner wall of the clamping groove 15 is fixedly connected with an anti-slip pad 16, the side wall of the anti-slip pad 16 is circular, the inner wall of the clamping groove 15 is fixedly connected with a stop lever 17, two ends of the stop lever 17 are fixedly connected with the inner side wall of the clamping groove 15, and the stop levers 17 are distributed in an annular array in the clamping groove 15;

furthermore, a threaded hole 18 is formed in the right end of the upper surface of the sealing cover 2, the lower end of the threaded hole 18 is communicated with the lower part of the sealing cover 2, a threaded rod 4 is connected to the inner wall of the threaded hole 18 in a threaded manner, a gasket 19 is fixedly sleeved at the lower end of the threaded rod 4, and the upper surface of the gasket 19 is in sliding connection with the lower surface of the sealing cover 2;

furthermore, the lower end of the threaded rod 4 is provided with a universal wheel 20, the universal wheel 20 is positioned below the sealing cover 2, the upper end of the threaded rod 4 is fixedly sleeved with a rotating disc 21, and the lower surface of the rotating disc 21 is in sliding connection with the upper surface of the sealing cover 2;

furthermore, the upper surface of the rotating disk 21 is provided with rotating grooves 22, the rotating grooves 22 are distributed on the surface of the rotating disk 21 in an annular array, the upper ends of the two threaded rods 4 are respectively provided with a second bearing 23, and the upper ends of the two second bearings 23 are fixedly connected with the same handle 24;

further, the display screen 25 is installed to the left side wall of sealed lid 2, and display screen 25 and wave recorder body 1 electric connection, the last fixed surface of wave recorder body 1 is connected with hasp keeping silent 26, and the last fixed surface of sealed lid 2 is connected with hasp tongue seat 27, and hasp keeping silent 26 and hasp tongue seat 27 overlap joint.

Have gyro wheel 14's antiskid through the lower surface mounting who sets up at the oscillograph, the rolling friction who utilizes gyro wheel 14 and ground replaces the sliding friction of oscillograph body 1 lower surface and ground, and then reduce coefficient of friction, be convenient for record the removal of oscillograph body 1, and simultaneously, utilize to support sealed lid 2 through universal wheel 20 at the lower extreme of sealed lid 2, the rolling friction who utilizes universal wheel 20 and ground replaces the sliding friction of sealed lid 2 lower surface and ground, and then reduce coefficient of friction, be convenient for seal the removal of lid 2, and support mutually through sealed lid 2 and oscillograph body 1, it moves together to drive the oscillograph through 24 sealed lid of handle pulling 2, thereby make and have the characteristics that the oscillograph of being convenient for removed in narrow and small space.

Through the specification that sets up universal wheel 20 and the interval adaptation between two pin 17 in the draw-in groove 15, when the record ripples appearance uses, the record ripples appearance level is placed, the left side wall and the ground contact of record ripples appearance body 1, place with the same level of record ripples appearance body 1 through adjustment gyro wheel 14, expand sealed lid 2, and utilize the rotary disk 21 on the 2 surfaces of rotatory sealed lid, drive threaded rod 4 through rotary disk 21 and descend, make the universal wheel 20 lower extreme of threaded rod 4 lower extreme stretch into in the draw-in groove 15, and support tightly with gag lever post 7 and the slipmat 16 of draw-in groove 15 inner wall, make gyro wheel 14 move the decline together with connecting, the sucking disc 11 and the ground of dead lever 10 lateral wall bond, and then carry out spacing fixed to record ripples appearance body 1, thereby make to have the characteristics that the record ripples appearance of being convenient for uses firmly.

Through setting up at the lower extreme installation gag lever post 7 of support column 3, with gag lever post 7 and the inside 8 sliding connection of spacing groove of connecting block 6, utilize the lower extreme of gag lever post 7 and the lower extreme surface adaptation of spacing groove 8, make gag lever post 7 and spacing groove 8 in vertical direction joint of each other, gag lever post 7 can freely translate in the horizontal direction, and support tightly through setting up spring 9 at the inside wall both ends of spacing groove 8 to the lateral wall of gag lever post 7, avoid gag lever post 7 too swing when the oscillograph walking, influence the walking, thereby make to have and be convenient for to the characteristics of control antiskid device operation.

The working principle is as follows:

the hasp tongue seat 27 is lapped with the hasp jaw 26, the wave recorder body 1 and the sealing cover 2 are placed in an upright mode to abut against the wave recorder body 1, the rotating disc 21 is rotated, the rotating disc 21 drives the threaded rod 4 to rotate, the threaded rod 4 drives the universal wheel 20 to descend, the lower end of the universal wheel 20 is aligned with the lower end of the roller 14 and supports the wave recorder, the handle 24 is pulled, the threaded rod 4 is pulled by the handle 24, the sealing cover 2 and the wave recorder body 1 are pulled, and the roller 14 and the universal wheel 20 are respectively driven to roll by the wave recorder body 1 and the sealing cover 2;

when the recorder is used, the recorder body 1 is horizontally laid down, the hasp jaw 26 and the hasp tongue 27 are opened, the adjusting roller 14 and the recorder body 1 are horizontally laid together, the sealing cover 2 is unfolded, the sealing cover 2 is lifted, the rotating disc 21 is rotated, the rotating disc 21 drives the threaded rod 4 to rotate together, the threaded rod 4 drives the universal wheel 20 to descend together, the lower end of the universal wheel 20 extends into the clamping groove 15, the lower end of the universal wheel 20 is abutted tightly through two adjacent stop levers 17 and the anti-slip pad 16, the roller 14 descends under the descending action of the universal wheel 20, the roller 14 drives the fixing rod 10 and the connecting block 6 to descend together, the side wall sucker 11 of the fixing rod 10 is in contact with the ground and is bonded with the ground, the connecting rod is communicated with the limiting groove 8 to descend, the limiting rod 7 ascends in the limiting groove 8, the spring 9 above the limiting rod 7 is extruded and deformed, and the spring 9 below the limiting rod 7 is stretched and deformed.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. The utility model provides a aerogenerator detects with narrow and small space running gear of oscillograph, includes oscillograph body (1), its characterized in that: the utility model discloses a wave recorder, including wave recorder body (1), the right side wall lower extreme of wave recorder body (1) articulates there is sealed lid (2), the lateral wall of sealed lid (2) and the lateral wall adaptation of wave recorder body (1) align, the left side wall sliding connection of sealed lid (2) has the right side wall of wave recorder body (1), antiskid is installed to the lower extreme of wave recorder body (1), through antiskid fixes the antiskid to the wave recorder when using, antiskid includes support column (3), the surface mounting of sealed lid (2) has running gear, through running gear reduces the friction of wave recorder and ground, running gear includes threaded rod (4).

2. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 1, is characterized in that: first bearing (5) are installed to the lower table left end of oscillograph body (1), the upper end of the inside wall fixedly connected with support column (3) of first bearing (5), the lower surface sliding connection of support column (3) has connecting block (6), the lower fixed surface of support column (3) is connected with gag lever post (7), spacing groove (8) have been seted up to the upper surface of connecting block (6).

3. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 2, is characterized in that: the inner wall sliding connection of gag lever post (8) has gag lever post (7), the equal fixedly connected with spring (9) of both sides wall of gag lever post (7), two the terminal two inside walls of fixedly connected with gag lever post (8) respectively of spring (9), the equal fixedly connected with dead lever (10) in lower surface both ends of connecting block (6).

4. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 3, is characterized in that: two equal fixedly connected with sucking disc (11) of the lateral wall lower extreme that backs on the back of the body of dead lever (10), two fixed orifices (12) have all been seted up to the lateral wall of dead lever (10), two the equal adaptation in surface of fixed orifices (12) aligns, two the inside wall of fixed orifices (12) is all fixed the grafting has same fixed axle (13).

5. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 4, is characterized in that: the surface mounting of fixed axle (13) has gyro wheel (14), gyro wheel (14) are located between two adjacent dead levers (10), the axis of gyro wheel (14) and the axis of fixed axle (13) all are on same straight line, draw-in groove (15) have all been seted up to the both sides wall of gyro wheel (14), the lateral wall of draw-in groove (15) is the ring form.

6. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 5, is characterized in that: the utility model discloses a novel anti-skidding card slot, including draw-in groove (15), the inner wall fixedly connected with slipmat (16) of draw-in groove (15), the lateral wall of slipmat (16) is the ring form, the inner wall fixedly connected with pin (17) of draw-in groove (15), the both ends of pin (17) all with the inside wall fixed connection of draw-in groove (15), pin (17) are the ring array and distribute in the inside of draw-in groove (15).

7. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 1, is characterized in that: threaded hole (18) are seted up to the upper surface right-hand member of sealed lid (2), the lower extreme intercommunication of threaded hole (18) has the below of sealed lid (2), the inner wall threaded connection of threaded hole (18) has threaded rod (4), the fixed cover of lower extreme of threaded rod (4) has been cup jointed packing ring (19), the upper surface of packing ring (19) and the lower surface sliding connection of sealed lid (2).

8. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 1, is characterized in that: universal wheel (20) are installed to the lower extreme of threaded rod (4), universal wheel (20) are located the below of sealed lid (2), the fixed cover in upper end of threaded rod (4) has connect rotary disk (21), the lower surface of rotary disk (21) and the upper surface sliding connection of sealed lid (2).

9. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 8, is characterized in that: rotatory groove (22) have been seted up to the upper surface of rotary disk (21), rotatory groove (22) are the annular array distribution on the surface of rotary disk (21), two second bearing (23), two are all installed to the upper end of threaded rod (4) the same handle (24) of upper end fixed connection of second bearing (23).

10. The narrow space traveling device of the wave recorder for wind driven generator detection as claimed in claim 1, is characterized in that: display screen (25) are installed to the left side wall of sealed lid (2), display screen (25) and record ripples appearance body (1) electric connection, the last fixed surface of record ripples appearance body (1) is connected with the hasp and keeps silent (26), the last fixed surface of sealed lid (2) is connected with hasp tongue seat (27), hasp keep silent (26) and hasp tongue seat (27) overlap joint.