CN115799807A

CN115799807A - Communication satellite antenna assembly

Info

Publication number: CN115799807A
Application number: CN202211653579.2A
Authority: CN
Inventors: 张振; 廖鲜明; 张泽钦
Original assignee: Shenzhen Tianweixun Wireless Technology Co ltd
Current assignee: Shenzhen Tianweixun Wireless Technology Co ltd
Priority date: 2022-12-22
Filing date: 2022-12-22
Publication date: 2023-03-14

Abstract

The invention relates to the technical field of communication satellite antennas, and discloses a communication satellite antenna assembly which comprises a base, wherein the inner wall of the base is connected with a first three fixing rods in a sliding manner, the inner wall of the first fixing rod is connected with a first threaded rod in a threaded manner, the top end of the first threaded rod is provided with a first universal joint, the output end of the first universal joint, which is far away from one side of the first threaded rod, is fixedly connected with an antenna body through a screw, the surface of the first fixing rod is provided with a clamping groove, the inner wall of the base is connected with an installation block in a sliding manner, the inner wall of the base is connected with a clamping plate in a sliding manner through an elastic part, one side of the clamping plate is mutually contacted with the inner wall of the clamping groove, and the other side of the clamping plate is mutually contacted with the surface of the installation block.

Description

Communication satellite antenna assembly

Technical Field

The invention relates to the technical field of communication satellite antennas, in particular to a communication satellite antenna assembly.

Background

The satellite antenna is a pot which is a metal paraboloid and is responsible for reflecting satellite signals to a feed source and a high-frequency head which are positioned at a focus, the satellite antenna is used for collecting weak signals transmitted by a satellite and removing noise as much as possible, and the satellite antenna is used for receiving the signals to communicate information transmission between the two places so as to achieve the purpose of communication.

Patent publication No. CN 213878381U's utility model discloses a communication satellite antenna mounting structure, include: a base; the supporting structure is detachably arranged in the right end of the base; the utility model relates to the technical field of satellite antennas, and relates to a satellite antenna, which comprises a base, a support structure, a balance plate, an adjusting structure and a supporting structure, wherein the adjusting structure is detachably arranged in the left end of the base and is movably connected with the support structure; the design is convenient to disassemble and assemble, the support is stable, the support does not need to be additionally fixed, meanwhile, the adjustment can be carried out after the installation, and the integral disassembly and transportation are convenient; however, the satellite antenna is very troublesome to mount, and needs to be welded or a plurality of bolts are needed to connect and fix the antenna and the bearing platform, so that a long time is needed to mount the satellite antenna, and the subsequent dismounting and maintenance are also very troublesome, so that a communication satellite antenna assembly is provided to solve the problems.

Disclosure of Invention

The invention aims to solve the technical problems that the conventional satellite antenna is very troublesome to mount, needs to be welded or needs a plurality of bolts to connect and fix the antenna and a bearing platform, needs a long time to mount the satellite antenna, and is very troublesome to subsequently dismount and maintain, and provides a communication satellite antenna assembly aiming at the defects in the prior art.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a communication satellite antenna assembly comprises a base, wherein the inner wall of the base is connected with a first three fixed rods in a sliding mode, the inner wall of the first fixed rod is connected with a first threaded rod in a threaded mode, the top end of the first threaded rod is provided with a first universal joint, the output end, far away from one side of the first threaded rod, of the first universal joint is fixedly connected with an antenna body through a screw, the surface of the first fixed rod is provided with a clamping groove, the inner wall of the base is connected with an installation block in a sliding mode, the inner wall of the base is connected with a clamping plate in a sliding mode through an elastic piece, during installation, the screw on the first three universal joints is rotated into the back face of the antenna body, the first fixed rod on the first universal joint is inserted into the corresponding base, the first threaded rod in threaded connection can be driven through rotation of the first fixed rod, the extending length of the first three fixed rods can be adjusted, the antenna body is guaranteed to be installed in an angle mode and can be adjusted at any time through the maximum receiving angle, and great convenience is achieved; one side of cardboard and the inner wall of draw-in groove contact each other, the opposite side of cardboard and the surface of installation piece contact each other, adjust the completion back, insert the installation piece in the base, at this moment the chamfer of installation piece below can promote the cardboard in the base and remove for three cardboard removes to the draw-in groove of dead lever one below, and then can carry on spacingly to dead lever one, makes the antenna can be quick by the installation, and the later stage is also conveniently dismantled.

Preferably, a transmission heating device is arranged at the top of the mounting block and comprises a motor, a second fixing rod is fixedly connected to the output end of the motor, a second threaded rod is connected to the inner wall of the second fixing rod in a threaded manner, a second universal joint is mounted at the top end of the second threaded rod, a rotary disc is fixedly connected to the output end of the second universal joint, which is far away from the second threaded rod, a convex block is fixedly connected to one side of the rotary disc, which is far away from the antenna body, a cam is fixedly connected to the surface of the second fixing rod, snow can cover the antenna body in winter to influence the collection of signals, and at the moment, a heating strip in the elastic plate can heat and melt the snow on the antenna body, so that the snow is prevented from continuously influencing the signal reception of the antenna body; the bottom of motor and the top fixed connection of installation piece, the one side that the lug was kept away from to the carousel contacts with the back of antenna body each other, and the motor can drive two rotations of dead lever, and two can drive the threaded rod two to reverse rotation of screwing for two drive universal joint two rotations of threaded rod, and two can drive the carousel rotation of universal joint, and it is rotatory that the carousel can drive the lug, and the rotation of lug can be strikeed with the elastic plate, and then makes the elastic plate take place deformation, makes freezing and snow on the elastic plate cracked and drop, promotes the rate of generating heat and the effect of elastic plate.

Preferably, the front side of the antenna body is provided with a rotary scraping device, the rotary scraping device comprises a scraping strip, the inner wall of the scraping strip is fixedly connected with an upper magnet, the inner wall of the turntable is fixedly connected with a lower magnet, the back side of the antenna body is fixedly connected with a plurality of elastic plates, the inner wall of the scraping strip is slidably connected with a sliding block through a spring, two sides of the sliding block are both fixedly connected with elastic rods, one end, far away from the sliding block, of each elastic rod is fixedly connected with a scraping block, the upper magnet is attracted through the lower magnet and the scraping strip is driven to rotate when the turntable rotates, snow on the concave part on the front side of the antenna body can be scraped through the rotation of the scraping strip, and the efficiency and the effect of snow cleaning are improved; the lower surface of scraping the strip and the front of antenna body between contact each other, go up magnetism and attract mutually between the magnet down, the carousel is kept away from one side of antenna body and the surface of elastic plate and is contacted each other, the internally mounted of elastic plate has the hot plate, scrape the surface of piece and the surface sliding connection of scraping the strip, the quantity of scraping the strip only sets up three or still less, can be fine prevent to scrape the strip and occupy the area of the great plane of reflection of antenna body, and then influence the reflection effect of counterface.

Preferably, the top of the base is fixedly connected with a collecting and discharging device, the collecting and discharging device comprises a supporting plate, the top of the supporting plate is fixedly connected with a collecting box, the rear part of the collecting box is fixedly connected with a solar panel and a heating machine respectively, the inner wall of the supporting plate is connected with a sliding plate in a sliding manner, a water outlet hole is formed in the surface of the sliding plate, the inner wall of the supporting plate is connected with a transmission plate in a sliding manner through an elastic part, the top of the transmission plate is fixedly connected with an inclined block, rain and snow can fall into the collecting box, in winter, a motor is started to drive a fixing rod II to rotate, the fixing rod II drives a cam to rotate, the cam rotates to push the transmission plate to a certain extent, the transmission plate can drive the inclined block to move, the inclined block can push the sliding plate to move upwards through the inclined plane, meanwhile, solar energy absorbed by the solar panel can be converted into electric energy and drive the heating machine to heat the rain and snow in the collecting box, so that the rain and snow can be melted, the sliding plate moves upwards to enable the water outlet hole to be communicated with a through hole in the front part of the collecting box, at this moment, water in the collecting box can flow out and flow into the antenna body, so that the melted liquid can be contacted with the frozen part on the antenna body, and can help to melt the frozen part of the frozen part to further prevent the scraping strip from rotating; the bottom of backup pad and the top fixed connection of base, the heater is located solar panel's below, and electric connection between heater and the solar panel, the surface of slide and the inner wall sliding connection who collects the box bottom, the top of sloping block and the bottom of slide contact each other, one side that the backup pad was kept away from to the driving plate and the surface of cam contact each other.

By adopting the technical scheme, the invention can bring the following beneficial effects:

1. this communication satellite antenna subassembly through the cooperation function between base, dead lever one, threaded rod one, universal joint one, antenna body, draw-in groove, installation piece, the cardboard for the antenna can be quick by the installation, the later stage is also conveniently dismantled.

2. This communication satellite antenna subassembly, through the motor, dead lever two, threaded rod two, universal joint two, the carousel, the lug, the cooperation function between the cam, heating strip in the elastic plate can heat and melt the snow on the antenna body, prevents that snow from continuing to influence the signal reception of antenna body, and the rotation of lug can strike with the elastic plate simultaneously, and then makes the elastic plate take place deformation for freeze on the elastic plate and snow is cracked to drop, promotes the speed of generating heat and the efficiency of elastic plate.

3. This communication satellite antenna subassembly through scrape the strip, go up magnet, down the cooperation function between magnet, the elastic plate, can attract magnet and drive to scrape the strip through magnet down and rotate when the carousel is rotatory, scrapes the rotation of strip and can strike off the positive concave snow of antenna body, promotes the efficiency and the effect of snow clearance.

4. This communication satellite antenna subassembly, through backup pad, collection box, solar panel, heater, slide, apopore, driving plate, the cooperation function between the sloping block, at this moment collect the box normal water can flow and flow into on the antenna body for the liquid that melts can with the contact of department of freezing on the antenna body, can help the department of freezing to melt on the antenna body rapidly, prevent the scraping strip because of freezing and then unable rotary motion.

Drawings

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

FIG. 2 is a schematic view of a multi-directional structure of a base according to the present invention;

FIG. 3 is a schematic view of a clip plate structure of the present invention;

FIG. 4 is a schematic view of a multi-directional structure of the motor of the present invention;

FIG. 5 is a schematic view of the structure of the scraping strip of the present invention;

FIG. 6 is a semi-sectional view of the wiper strip construction of the present invention;

FIG. 7 is a half sectional view of the support plate structure of the present invention.

In the figure: 1. a base; 2. a transmission heating device; 21. a motor; 22. a second fixing rod; 23. a second threaded rod; 24. a second universal joint; 25. a turntable; 26. a bump; 27. a cam; 3. a rotating scraping device; 31. scraping the strips; 32. an upper magnet; 33. a lower magnet; 34. an elastic plate; 35. a slider; 36. an elastic rod; 37. scraping the block; 4. a collecting and discharging device; 41. a support plate; 42. a collection box; 43. a solar panel; 44. a heater; 45. a slide plate; 46. a water outlet hole; 47. a drive plate; 48. a sloping block; 5. fixing a rod I; 6. a first threaded rod; 7. a first universal joint; 8. an antenna body; 9. a card slot; 10. mounting a block; 11. provided is a clamping plate.

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. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Examples

A communication satellite antenna assembly is shown in figures 1-7 and comprises a base 1, wherein the inner wall of the base 1 is connected with three first fixing rods 5 in a sliding mode, the inner wall of each first fixing rod 5 is connected with a first threaded rod 6 in a threaded mode, a first universal joint 7 is installed at the top end of each first threaded rod 6, the output end, far away from one side of each first threaded rod 6, of each first universal joint 7 is fixedly connected with an antenna body 8 through a screw, the surface of each first fixing rod 5 is provided with a clamping groove 9, the inner wall of the base 1 is connected with an installation block 10 in a sliding mode, the inner wall of the base 1 is connected with a clamping plate 11 in a sliding mode through an elastic piece, during installation, the screws on the three first universal joints 7 are rotated into the back face of the antenna body 8, the first fixing rods 5 on the first universal joints 7 are inserted into the corresponding base 1, at the moment, the first threaded rods 6 in threaded connection can be driven by rotating the first fixing rods 5, the extending lengths of the first threaded rods 5 can be adjusted, and the antenna body 8 can be installed in an angle and adjusted at any time through the maximum receiving angle, and great convenience is achieved; one side of cardboard 11 and draw-in groove 9's inner wall contaction each other, cardboard 11's opposite side and installation piece 10's surface contaction each other, adjust and accomplish the back, insert installation piece 10 in base 1, at this moment, the chamfer of installation piece 10 below can promote cardboard 11 in the base 1 and remove, make three cardboard 11 remove to the draw-in groove 9 of dead lever 5 below, and then can carry on spacingly to dead lever 5, make the antenna can be quick by the installation, the later stage is also conveniently dismantled.

The top of the mounting block 10 is provided with a transmission heating device 2, the transmission heating device 2 comprises a motor 21, the output end of the motor 21 is fixedly connected with a second fixing rod 22, the inner wall of the second fixing rod 22 is in threaded connection with a second threaded rod 23, the top end of the second threaded rod 23 is provided with a second universal joint 24, the output end of the second universal joint 24, which is far away from one side of the second threaded rod 23, is fixedly connected with a rotary disc 25, one side of the rotary disc 25, which is far away from the antenna body 8, is fixedly connected with a convex block 26, and the surface of the second fixing rod 22 is fixedly connected with a cam 27; the bottom of motor 21 and the top fixed connection of installation piece 10, one side that lug 26 was kept away from to carousel 25 and the back of antenna body 8 contact each other, motor 21 can drive two dead lever 22 rotatoryly, two dead lever 22 can drive two threaded rods 23 to the reverse rotation of screwing, make two threaded rod 23 drive two universal joint 24 rotatoryly, two universal joint 24 can drive the carousel 25 rotatoryly, carousel 25 can drive lug 26 rotatoryly, lug 26's rotation can strike with elastic plate 34, and then make elastic plate 34 take place deformation, make icing and snow on the elastic plate 34 cracked and drop, promote elastic plate 34's the speed of generating heat and effect.

The front side of the antenna body 8 is provided with the rotary scraping device 3, the rotary scraping device 3 comprises a scraping strip 31, an upper magnet 32 is fixedly connected to the inner wall of the scraping strip 31, a lower magnet 33 is fixedly connected to the inner wall of the turntable 25, a plurality of elastic plates 34 are fixedly connected to the back side of the antenna body 8, a slider 35 is slidably connected to the inner wall of the scraping strip 31 through a spring, elastic rods 36 are fixedly connected to both sides of the slider 35, a scraping block 37 is fixedly connected to one end, far away from the slider 35, of each elastic rod 36, the upper magnet 32 is attracted through the lower magnet 33 and the scraping strip 31 is driven to rotate when the turntable 25 rotates, snow on the concave portion of the front side of the antenna body 8 can be scraped through the rotation of the scraping strip 31, and the snow cleaning efficiency and effect are improved; mutual contact between the lower surface of scraping strip 31 and the front of antenna body 8, go up magnetism between magnet 32 and the lower magnet 33 and inhale mutually, the one side that carousel 25 kept away from antenna body 8 and the surface of elastic plate 34 contact mutually, the internally mounted of elastic plate 34 has the hot plate, scrape the surface of piece 37 and the surface sliding connection of scraping strip 31, the quantity of scraping strip 31 only sets up three or less, can be fine prevent that scraping strip 31 from taking up the area of the great plane of reflection of antenna body 8, and then influence the reflection effect of reverse side, its inside slider 35 can remove and drive elastic rod 36 removal under the centrifugal force effect when scraping strip 31 rotates, elastic rod 36 can push away the ice that scrapes 37 surface adhesion of piece, make the unable adhesion of crushed ice be at the surface of scraping strip 31, the rotation of scraping strip 31 can push the crushed ice to the antenna outside through centrifugal force until the crushed ice is thrown away outside the antenna.

The top of the base 1 is fixedly connected with a collecting and discharging device 4, the collecting and discharging device 4 comprises a supporting plate 41, the top of the supporting plate 41 is fixedly connected with a collecting box 42, the rear part of the collecting box 42 is respectively and fixedly connected with a solar panel 43 and a heater 44, the inner wall of the supporting plate 41 is in sliding connection with a sliding plate 45, a water outlet hole 46 is formed in the surface of the sliding plate 45, the inner wall of the supporting plate 41 is in sliding connection with a transmission plate 47 through an elastic piece, the top of the transmission plate 47 is fixedly connected with an inclined block 48, rain and snow fall into the collecting box 42, in winter, when the motor 21 is started, the fixing rod two 22 can drive the cam 27 to rotate, the cam 27 rotates to push the transmission plate 47 to be certain, the transmission plate 47 can drive the inclined block 48 to move, the inclined block 48 can push the sliding plate 45 to move upwards through an inclined plane, meanwhile, solar energy absorbed by the solar panel 43 can be converted into electric energy and drive the heater 44 to heat the rain and snow in the collecting box 42 to melt the ice, at the ice at the water outlet hole 46 in the front part of the collecting box 42 can be communicated with a through hole of the collecting box 42, water in the collecting box 42 can flow out and flow into the antenna body 8, so that liquid at the melted on the antenna 8, and the antenna body can be prevented from being scraped, and the antenna body 31, and the ice bar can be prevented from rotating; the bottom of backup pad 41 and the top fixed connection of base 1, heater 44 are located the below of solar panel 43, and electric connection between heater 44 and the solar panel 43, the surface of slide 45 and the inner wall sliding connection who collects the box 42 bottom, the top of sloping block 48 and the bottom of slide 45 contact each other, one side that backup pad 41 was kept away from to driving plate 47 and the surface of cam 27 contact each other.

According to the working principle, during installation, screws on the first universal joints 7 are rotated into the back of the antenna body 8, the first fixing rods 5 on the first universal joints 7 are inserted into the corresponding bases 1, at the moment, the first fixing rods 5 are rotated to drive the first threaded rods 6 in threaded connection, the extending lengths of the first threaded rods 6 on the first fixing rods 5 can be adjusted, the antenna body 8 is guaranteed to be installed in an angle mode and adjusted at any time through the maximum receiving angle, the operation is very convenient, after the adjustment is completed, the installation block 10 is inserted into the bases 1, at the moment, the clamping plates 11 in the bases 1 are pushed to move by the chamfer angles below the installation block 10, the three clamping plates 11 are moved into the clamping grooves 9 below the first fixing rods 5, the first fixing rods 5 can be limited, the antenna can be installed quickly, and the antenna can be detached conveniently in the later period;

in winter, snow can cover the antenna body 8 to affect signal collection, at this time, the heating strips in the elastic plate 34 can heat and melt snow on the antenna body 8, so that the snow can be prevented from continuously affecting signal reception of the antenna body 8, meanwhile, the motor 21 can drive the second fixing rod 22 to rotate, the second fixing rod 22 can drive the second threaded rod 23 to rotate in the opposite direction of screwing, the second threaded rod 23 can drive the second universal joint 24 to rotate, the second universal joint 24 can drive the rotary disc 25 to rotate, the rotary disc 25 can drive the lug 26 to rotate, the rotation of the lug 26 can impact the elastic plate 34, and then the elastic plate 34 is deformed, so that the frozen snow and snow on the elastic plate 34 can be broken and fall off, and the heating speed and efficiency of the elastic plate 34 are improved;

when the turntable 25 rotates, the lower magnet 33 attracts the upper magnet 32 and drives the scraping strips 31 to rotate, snow at the concave position on the front surface of the antenna body 8 can be scraped by the rotation of the scraping strips 31, the snow cleaning efficiency and effect are improved, and the number of the scraping strips 31 is only three or less, so that the scraping strips 31 can be well prevented from occupying the area of a larger reflecting surface of the antenna body 8, and the reflecting effect of a reverse surface is further influenced;

rain and snow can fall into collection box 42, in winter, motor 21 starts and can drive two dead lever 22 rotatoryly, two dead lever 22 can drive cam 27 rotatoryly, cam 27 is rotatory and can promote driving plate 47 certainly, driving plate 47 can drive sloping block 48 and remove, sloping block 48 can promote slide 45 through the inclined plane and move up, meanwhile, the solar energy that solar panel 43 absorbs can turn into the electric energy and drive heater 44 and will collect rain and snow in the box 42 and heat, make it melt, at this moment, the shifting up of slide 45 can make apopore 46 and the anterior through-hole intercommunication of collection box 42, at this moment, collect box 42 in the water can flow out and flow into on the antenna body 8, make the liquid that melts can contact with the freezing department on the antenna body 8, can help the freezing department on the antenna body 8 to preliminarily melt rapidly, prevent to scrape strip 31 because of then unable rotary motion, promote to scrape the effect that the deicing was scraped to strip 31 simultaneously.

While the present invention provides a communication satellite antenna assembly and a number of ways to implement the same, it is to be understood that the foregoing is merely a preferred embodiment of the present invention, and that various modifications and adaptations may be made by those skilled in the art without departing from the principles of the present invention and should be considered within the scope of the present invention. All the components not specified in the present embodiment can be realized by the prior art.

Claims

1. A communication satellite antenna assembly comprising a base (1), characterized in that: the inner wall sliding connection of base (1) has three dead lever (5), the inner wall threaded connection of dead lever (5) has threaded rod (6), universal joint (7) are installed on the top of threaded rod (6), the output that threaded rod (6) one side was kept away from in universal joint (7) passes through screw fixedly connected with antenna body (8), draw-in groove (9) have been seted up on the surface of dead lever (5), the inner wall sliding connection of base (1) has installation piece (10), the inner wall of base (1) has cardboard (11) through elastic component sliding connection.

2. The antenna assembly of claim 1, wherein: one side of the clamping plate (11) is in mutual contact with the inner wall of the clamping groove (9), and the other side of the clamping plate (11) is in mutual contact with the surface of the mounting block (10).

3. The antenna assembly of claim 1, wherein: the top of installation piece (10) is provided with transmission heating device (2), transmission heating device (2) is including motor (21), the output end fixedly connected with dead lever two (22) of motor (21), the inner wall threaded connection of dead lever two (22) has threaded rod two (23), universal joint two (24) are installed on the top of threaded rod two (23), output fixedly connected with carousel (25) of threaded rod two (23) one side are kept away from in universal joint two (24), one side fixedly connected with lug (26) of antenna body (8) are kept away from in carousel (25), the fixed surface of dead lever two (22) is connected with cam (27).

4. A communications satellite antenna assembly as claimed in claim 3, wherein: the bottom of the motor (21) is fixedly connected with the top of the mounting block (10), and one side, far away from the bump (26), of the rotary disc (25) is in contact with the back of the antenna body (8).

5. The antenna assembly of claim 4, wherein: the front of antenna body (8) is provided with rotatory scraping device (3), rotatory scraping device (3) is including scraping strip (31), scrape magnet (32) on the inner wall fixedly connected with of strip (31), magnet (33) under the inner wall fixedly connected with of carousel (25), a plurality of elastic plate (34) of back fixedly connected with of antenna body (8), the inner wall of scraping strip (31) has slider (35) through spring sliding connection, the equal fixedly connected with elastic rod (36) in both sides of slider (35), the one end fixedly connected with that slider (35) were kept away from in elastic rod (36) scrapes piece (37).

6. The antenna assembly of claim 5, wherein: the lower surface of scraping strip (31) and the front of antenna body (8) contact each other, go up magnet (32) and attract mutually with magnetism down between magnet (33), one side that antenna body (8) were kept away from in carousel (25) and the surface of elastic plate (34) contact each other, the internally mounted of elastic plate (34) has the hot plate, scrape the surface of piece (37) and the surface sliding connection who scrapes strip (31).

7. A communications satellite antenna assembly as claimed in claim 3, wherein: discharging device (4) are collected to the top fixedly connected with of base (1), collect discharging device (4) including backup pad (41), box (42) are collected to the top fixedly connected with of backup pad (41), the rear portion difference fixedly connected with solar panel (43) and heater (44) of collecting box (42), the inner wall sliding connection of backup pad (41) has slide (45), apopore (46) have been seted up on the surface of slide (45), the inner wall of backup pad (41) has driving plate (47) through elastic component sliding connection, the top fixedly connected with sloping block (48) of driving plate (47).

8. The communication satellite antenna assembly of claim 7, wherein: the bottom of backup pad (41) and the top fixed connection of base (1), heater (44) are located solar panel (43)'s below, and electric connection between heater (44) and solar panel (43), the surface of slide (45) and the inner wall sliding connection who collects box (42) bottom, the top of sloping block (48) and the bottom of slide (45) contact each other, one side that backup pad (41) were kept away from in driving plate (47) and the surface of cam (27) contact each other.