An automatic discharging device for a vibration grinding machine

Abstract

The present invention discloses an automatic discharging device for a vibration grinding machine, which comprises a grinding machine. A central column is arranged at the center of the grinding machine. A grinding annular groove is formed between the central column and the inner wall of the grinding machine. A lifting hopper is sleeved above the grinding machine. A hopper sleeve is arranged at a position corresponding to the central column on the lifting hopper. An annular material groove is formed between the hopper sleeve and the lifting hopper. A plurality of filter holes are uniformly formed in the annular material groove. A support plate is arranged at the outer edge of the upper end of the lifting hopper. A blanking chute opening is formed at one side of the lifting hopper. A pair of front arm electric lifting rods are symmetrically fixed on the left and right of the outer wall of the grinding machine close to the blanking chute opening. A pair of rear arm electric lifting rods are symmetrically fixed on the outer wall of the grinding machine far from the blanking chute opening. A conveying device is correspondingly arranged at the end of the blanking chute opening. The present invention can fully automatically complete grinding, discharging and preparation for the next grinding operation, with a high degree of automation.

Description

Technical Field

[0001] The present invention relates to the field of grinding machines, and particularly to an automatic discharging device for a vibrating grinding machine. Background Art

[0002] A vibrating grinding machine is an industrial grinding machine mainly used for grinding and processing metal components, such as aluminum die-castings, zinc die-castings, furniture hardware, etc. Its working principle is that the driving motor drives the eccentric block in the vibrator to rotate, generating an exciting force, causing the grinding machine cylinder to produce high-frequency vibrations on the supporting springs, and grinding materials through projectile motion, co-rotating motion in the same direction, and revolution motion.

[0003] After the grinding operation is completed, it is often necessary to manually screen the materials from the grinding media. The working process is cumbersome, time-consuming and laborious. Therefore, an automatic discharging device for a vibrating grinding machine is needed. However, the existing automatic discharging devices still cannot completely separate the materials and the grinding media, resulting in some grinding media being mixed in during discharging, and still requiring manual operation, with low automation.

[0004] The invention patent with application number CN202121935852.1 discloses an automatic discharging device for a vibrating grinding machine. It hinges a guiding plate inside the grinding machine, and sets a driving device beside the grinding machine to lift and lower the guiding plate. The lifted guiding plate can convey the spiral-flowing grinding stones and workpieces together to a sieve fixed on the grinding machine. The sieve screens the grinding stones back into the grinding machine, and the workpieces finally enter the collecting device connected behind through the discharging port fixed on the grinding machine. The collecting device includes an inclined plate, a support frame for supporting the inclined plate, a conveying roller and a reversing device arranged on the inclined plate, and a second driving device for driving the conveying roller to operate, for discharging and collecting the ground materials.

[0005] Obviously, when discharging, this patent still requires manual operation to lift and lower the driving device of the guiding plate, with low automation. Most importantly, while collecting materials on the inclined plate, some grinding media will also follow the materials into the inclined plate, and the grinding media and materials cannot be completely separated, resulting in the collected materials still being mixed with grinding media.

[0006] In order to improve the automation of discharging of the vibrating grinding machine and avoid grinding media from mixing into the discharging device, the present invention provides an automatic discharging device for a vibrating grinding machine. Summary of the Invention

[0007] The purpose of the present invention is to provide an automatic discharging device for a vibrating grinding machine to solve the problems raised in the above background art.

[0008] To achieve the above object, the present invention provides the following technical solution: An automatic discharging device for a vibration grinding machine, including a grinding machine, a central column is provided at the center of the grinding machine, and a grinding ring groove is formed between the central column and the inner wall of the grinding machine. A lifting hopper is sleeved above the grinding machine. A hopper sleeve is provided at a position corresponding to the central column on the lifting hopper. The hopper sleeve is sleeved on the central column. The hopper sleeve and the lifting hopper form an annular material groove. A plurality of filter holes are evenly opened in the annular material groove. The filter holes are used for filtering abrasive materials. A support plate is provided at the outer edge of the upper end of the lifting hopper. A feeding chute opening is provided on one side of the lifting hopper. A pair of front arm electric lifting rods are symmetrically fixed on the left and right sides of the outer wall of the grinding machine near the feeding chute opening. A pair of rear arm electric lifting rods are symmetrically fixed on the outer wall of the grinding machine far from the feeding chute opening. The telescopic ends of the front arm electric lifting rods and the rear arm electric lifting rods are both hinged to the support plate. A conveying device is correspondingly arranged at the end of the feeding chute opening.

[0009] Further, the conveying device includes a support frame and a conveyor belt. A driving wheel and a driven wheel are respectively arranged at both ends of the conveyor belt. Guard plates are arranged on both sides of the conveyor belt.

[0010] Further, when the lifting hopper is completely sleeved with the grinding machine, the front arm electric lifting rods and the rear arm electric lifting rods are both in the shortest arm length state. A pressure sensor is arranged at the connection between one of the front arm electric lifting rods and the support plate.

[0011] Further, a rolling limit switch is embedded and fixed on the outer wall of the upper part of the central column. The roller of the rolling limit switch is exposed on the outer wall of the central column. When the hopper sleeve is sleeved with the central column, the inner wall of the hopper sleeve presses the rolling limit switch to close. When the hopper sleeve is separated from the central column, the rolling limit switch is disconnected.

[0012] Further, a controller is arranged in the grinding machine. After grinding is completed, the front arm electric lifting rods and the rear arm electric lifting rods are simultaneously started to rise synchronously, so that the hopper sleeve of the lifting hopper is separated from the central column. When the controller receives the signal that the rolling limit switch is disconnected, it controls the front arm electric lifting rods and the rear arm electric lifting rods to disconnect simultaneously, and at the same time, the vibration grinding machine continues to work, so that the abrasive material in the lifting hopper falls off from the filter holes and enters the grinding ring groove.

[0013] Further, the width of the conveyor belt is greater than the width of the feeding chute opening. An optoelectronic emitter is arranged at the front end of the guard plate. Optoelectronic receivers are arranged at the front ends of the support plates on the left and right sides of the feeding chute opening. The optoelectronic emitter and the optoelectronic receiver are horizontally aligned.

[0014] Further, the controller real-time collects the pressure value of the pressure sensor, and records the difference between the maximum value and the minimum value of the pressure value as the pressure amplitude. When the pressure amplitude tends to be stable, all the abrasive enters the grinding ring groove. At this time, the controller starts the synchronous lifting of the front arm electric lifting rod and the rear arm electric lifting rod again. When the photoelectric receiver receives the photoelectric signal, the height of the blanking chute opening is greater than the height of the conveyor belt. At this time, the front arm electric lifting rod stops, and the rear arm electric lifting rod continues to rise to the maximum arm length, so that the lifting hopper tilts towards the conveyor device side to pour the ground material. During the process of pouring the material, the grinding machine continues to work. The controller real-time collects the pressure value of the pressure sensor, and records the difference between the maximum value and the minimum value of the pressure value as the pressure amplitude. When the pressure amplitude tends to be stable, all the ground material enters the conveyor device, and the controller starts the front arm electric lifting rod and the rear arm electric lifting rod to descend to the shortest arm length.

[0015] Further, springs are fixed at the telescopic ends of the front arm electric lifting rod and the rear arm electric lifting rod, and are hinged to the support plate through the springs.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. By setting the front arm electric lifting rod and the rear arm electric lifting rod, the present invention enables the lifting hopper to be sleeved with and separated from the grinding machine. After grinding is completed, the front arm electric lifting rod and the rear arm electric lifting rod are started simultaneously to rise synchronously, so that the hopper sleeve of the lifting hopper is separated from the central column. When the controller receives the signal that the rolling limit switch is disconnected, it controls the front arm electric lifting rod and the rear arm electric lifting rod to disconnect simultaneously. At the same time, the vibrating grinding machine continues to work, so that the abrasive in the lifting hopper detaches from the filter holes and enters the grinding ring groove, thereby effectively separating the abrasive and the material, facilitating the discharge of the material. When the front arm electric lifting rod stops and the rear arm electric lifting rod continues to rise to the maximum arm length, the lifting hopper tilts towards the conveyor device side to pour the ground material, thus completing the automatic discharging of the grinding machine;

[0018] 2. During the process of pouring the material, the controller real-time collects the pressure value of the pressure sensor, and records the difference between the maximum value and the minimum value of the pressure value as the pressure amplitude. When the pressure amplitude tends to be stable, all the ground material enters the conveyor device, and the controller starts the front arm electric lifting rod and the rear arm electric lifting rod to descend to the shortest arm length, so that the lifting hopper is sleeved with the grinding machine again to prepare for the next grinding operation. Thereby, it can complete the grinding, discharging and preparation for the next grinding operation fully automatically, with a high degree of automation, and without manual screening, greatly reducing the labor force and improving the intelligence of the grinding operation;

[0019] 3. In the present invention, springs are fixed at the telescopic ends of both the forearm electric lifting rod and the rear arm electric lifting rod, and the springs are hinged to the support plate. When the lifting hopper and the grinding machine are sleeved again, hard contact between the annular material groove and the abrasive is avoided. During the grinding operation, due to the action of the springs, the annular material groove vibrates up and down, which will cause the abrasive to gradually enter the annular material groove and contact the material to be ground. At the same time, this up-and-down vibration also further improves the grinding effect. When pouring materials, due to the setting of the springs, the vibration generated during the operation of the grinding machine causes the springs to vibrate up and down, which also further improves the discharging speed and discharging effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of the grinding part of the automatic discharging device of a vibration grinding machine according to the present invention;

[0021] Figure 2 is a schematic sectional view of the grinding part of the automatic discharging device of a vibration grinding machine according to the present invention;

[0022] Figure 3 is a schematic structural diagram of the grinding machine of the automatic discharging device of a vibration grinding machine according to the present invention;

[0023] Figure 4 is a schematic structural diagram of the lifting hopper of the automatic discharging device of a vibration grinding machine according to the present invention;

[0024] Figure 5 is a top view of the lifting hopper of the automatic discharging device of a vibration grinding machine according to the present invention;

[0025] Figure 6 is a schematic sectional view of the lifting hopper of the automatic discharging device of a vibration grinding machine according to the present invention;

[0026] Figure 7 is a schematic overall structural diagram of the automatic discharging device of a vibration grinding machine according to the present invention;

[0027] Figure 8 is Figure 7 an enlarged schematic view of part A in

[0028] Figure 9 is Figure 7 an enlarged schematic view of part B in

[0029] Figure 10 is a discharging schematic view of the automatic discharging device of a vibration grinding machine according to the present invention;

[0030] Figure 11 is a schematic structural diagram of the grinding part of the automatic discharging device of the vibration grinding machine in Embodiment 3 of the present invention.

[0031] In the figure: 1. Grinding machine; 11. Central column; 12. Grinding ring groove; 2. Lifting hopper; 21. Hopper sleeve; 22. Annular material groove; 23. Filter holes; 24. Support plate; 25. Material discharge slot; 3. Electric lifting rod for the front arm; 4. Electric lifting rod for the rear arm; 5. Conveying device; 51. Support frame; 52. Conveyor belt; 53. Driving wheel; 54. Driven wheel; 55. Guard plate; 6. Spring; 7. Photoelectric emitter; 8. Photoelectric receiver; 9. Rolling limit switch; 10. Vibration motor. Specific implementation mode

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Embodiment 1

[0034] Please refer to Figures 1-10 , the present invention provides a technical solution: an automatic discharging device for a vibrating grinding machine, including a grinding machine 1. A central column 11 is arranged at the center of the grinding machine 1. A grinding ring groove 12 is formed between the central column 11 and the inner wall of the grinding machine 1. A lifting hopper 2 is sleeved above the grinding machine 1. A hopper sleeve 21 is arranged at the corresponding position of the lifting hopper 2 and the central column 11. The hopper sleeve 21 is sleeved on the central column 11. An annular material groove 22 is formed between the hopper sleeve 21 and the lifting hopper 2. The inner wall of the annular material groove 22 is smooth. A number of filter holes 23 are evenly arranged in the annular material groove 22. The filter holes 23 are used for filtering the grinding material. A rolling limit switch 9 is fixedly embedded on the outer wall of the upper part of the central column 11. The roller of the rolling limit switch 9 is exposed on the outer wall of the central column 11. When the hopper sleeve 21 is sleeved with the central column 11, the inner wall of the hopper sleeve 21 presses the rolling limit switch 9 to close. When the hopper sleeve 21 is separated from the central column 11, the rolling limit switch 9 is disconnected.

[0035] A support plate 24 is arranged at the outer edge of the upper end of the lifting hopper 2. A material discharge slot 25 is arranged on one side of the lifting hopper 2. When the lifting hopper 2 is completely sleeved with the grinding machine 1, both the electric lifting rod 3 for the front arm and the electric lifting rod 4 for the rear arm are in the shortest arm length state.

[0036] When the lifting hopper 2 is completely sleeved with the grinding machine 1, the grinding material enters the annular material groove 22 through the filter holes 23 and comes into full contact with the material to be ground, and the grinding operation is carried out. At the same time, through the vibration of the vibration motor 10, the central column 11 and the hopper sleeve 21 perform eccentric vibration, so that the grinding material and the material to be ground in the annular material groove 22 of the grinding hopper 2 continuously roll and rotate along the annular material groove 22 for friction, and the surface of the material to be ground is ground.

[0037] On the outer wall of the grinding machine 1 near the blanking chute opening 25, a pair of front-arm electric lifting rods 3 are symmetrically fixed on the left and right. On the outer wall of the grinding machine 1 far from the blanking chute opening 25, a pair of rear-arm electric lifting rods 4 are symmetrically fixed. The telescopic ends of the front-arm electric lifting rods 3 and the rear-arm electric lifting rods 4 are both hinged to the support plate 24. By lifting the front-arm electric lifting rods 3 and the rear-arm electric lifting rods 4, the lifting hopper 2 can be lifted, so that the lifting hopper 2 can be sleeved with and separated from the grinding machine 1.

[0038] Among them, a controller is arranged in the grinding machine 1. After grinding is completed, the front-arm electric lifting rods 3 and the rear-arm electric lifting rods 4 are simultaneously started to rise synchronously, so that the hopper sleeve 21 of the lifting hopper 2 is separated from the central column 11. When the controller receives the signal that the rolling limit switch 9 is disconnected, it controls the front-arm electric lifting rods 3 and the rear-arm electric lifting rods 4 to disconnect at the same time, and the vibrating grinding machine continues to work, so that the grinding material in the lifting hopper 2 falls off from the filter holes 23 and enters the grinding ring groove 12.

[0039] Among them, a conveying device 5 is correspondingly arranged at the end of the blanking chute opening 25. The conveying device 5 includes a support frame 51 and a conveyor belt 52. The two ends of the conveyor belt 52 are respectively provided with a driving wheel 53 and a driven wheel 54. Both sides of the conveyor belt 52 are provided with guard plates 55. The width of the conveyor belt 52 is greater than the width of the blanking chute opening 25. An optical transmitter 7 is arranged at the front end of the guard plate 55. Optical receivers 8 are arranged at the front ends of the support plates 24 on the left and right sides of the blanking chute opening 25. The optical transmitter 7 and the optical receiver 8 are horizontally aligned. When the controller starts the front-arm electric lifting rods 3 and the rear-arm electric lifting rods 4 to rise synchronously again, when the optical receiver 8 receives the optical signal, the height of the blanking chute opening 25 is greater than the height of the conveyor belt 52. At this time, the front-arm electric lifting rods 3 stop, and the rear-arm electric lifting rods 4 continue to rise to the maximum arm length, so that the lifting hopper 2 tilts towards the conveying device 5 to pour the ground material, thus completing the automatic discharging of the grinding machine.

[0040] Embodiment 2

[0041] In order to avoid the residue of abrasive during discharging, further improve the automation degree of discharging, and enable the abrasive to completely detach from the filter holes 23 and enter the grinding ring groove 12, in this embodiment, a pressure sensor is provided at the connection between one of the front-arm electric lifting rods 3 and the support plate 24. The controller collects the pressure value of the pressure sensor in real time, and records the difference between the maximum value and the minimum value of the pressure value as the pressure amplitude. When the pressure amplitude tends to be stable, it means that all the abrasive has entered the grinding ring groove 12. At this time, the controller starts the front-arm electric lifting rod 3 and the rear-arm electric lifting rod 4 to rise synchronously again. When the photoelectric receiver 8 receives the photoelectric signal, the height of the blanking chute opening 25 is greater than the height of the conveyor belt 52. At this time, the front-arm electric lifting rod 3 stops, and the rear-arm electric lifting rod 4 continues to rise to the maximum arm length, causing the lifting hopper 2 to tilt towards the conveying device 5 to pour out the ground material.

[0042] Reference Figure 10 , during the process of pouring the material, the grinding machine continues to work. The controller collects the pressure value of the pressure sensor in real time, and records the difference between the maximum value and the minimum value of the pressure value as the pressure amplitude. When the pressure amplitude tends to be stable, it means that all the ground material has entered the conveying device 5. The controller starts the front-arm electric lifting rod 3 and the rear-arm electric lifting rod 4 to descend to the shortest arm length, causing the lifting hopper 2 and the grinding machine 1 to fit together again to prepare for the next grinding operation. In this way, the grinding, discharging, and preparation for the next grinding operation can be completed fully automatically, with a high degree of automation and no need for manual screening, greatly reducing the labor force and improving the intelligence of the grinding operation.

[0043] Embodiment 3

[0044] During actual production operations, the inventor found that after pouring the material, when the front-arm electric lifting rod 3 and the rear-arm electric lifting rod 4 descend to drive the lifting hopper 2 and the grinding machine 1 to fit together, the abrasive in the grinding ring groove 12 cannot smoothly pass through the filter holes 23 and enter the annular material groove 22 again, which hinders the fitting of the lifting hopper 2 and the grinding machine 1. After long-term use, the bottom of the annular material groove 22 of the lifting hopper 2 is deformed.

[0045] Reference Figure 11, in order to further improve the continuous operation ability of the grinding machine 1 and extend its service life, in this embodiment, springs 6 are fixed at the telescopic ends of the front arm electric lifting rod 3 and the rear arm electric lifting rod 4, and are hinged to the support plate 24 through the springs 6. A pressure sensor is provided at the connection between the spring 6 at the telescopic end of one of the front arm electric lifting rods 3 and the support plate 24. In this way, when the controller starts the front arm electric lifting rod 3 and the rear arm electric lifting rod 4 to descend to the shortest arm length, so that the lifting hopper 2 and the grinding machine 1 are sleeved again, even if the abrasive in the grinding ring groove 12 cannot completely enter the annular material groove 22 through the filter holes 23 again, but under the buffering action of the spring 6, the hard contact between the annular material groove 22 and the abrasive is avoided. During the grinding operation, due to the action of the spring 6, the annular material groove 22 vibrates up and down, which will cause the abrasive to gradually enter the annular material groove 22 to contact the material to be ground. At the same time, this up and down vibration also further improves the grinding effect. When pouring the material, due to the setting of the spring 6, the vibration generated during the operation of the grinding machine causes the spring 6 to vibrate up and down, which also further improves the discharging speed and discharging effect.

[0046] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic discharging device for a vibration grinding machine, comprising a grinding machine (1), characterized in that: A central column (11) is provided at the center of the grinding machine (1), and a grinding ring groove (12) is formed between the central column (11) and the inner wall of the grinding machine (1). An elevating hopper (2) is sleeved above the grinding machine (1). A hopper sleeve (21) is provided at a position corresponding to the central column (11) on the elevating hopper (2). The hopper sleeve (21) is sleeved on the central column (11). An annular material groove (22) is formed between the hopper sleeve (21) and the elevating hopper (2). A plurality of filter holes (23) are evenly formed in the annular material groove (22). The filter holes (23) are used for filtering abrasive. A support plate (24) is provided at the outer edge of the upper end of the elevating hopper (2). A blanking chute opening (25) is formed on one side of the elevating hopper (2). A pair of front arm electric elevating rods (3) are symmetrically and fixedly arranged on the left and right of the outer wall of the grinding machine (1) close to the blanking chute opening (25). A pair of rear arm electric elevating rods (4) are symmetrically and fixedly arranged on the outer wall of the grinding machine (1) far from the blanking chute opening (25). The telescopic ends of the front arm electric elevating rods (3) and the rear arm electric elevating rods (4) are both hinged to the support plate (24). A conveying device (5) is correspondingly arranged at the end of the blanking chute opening (25).

2. The automatic discharging device of a vibration grinding machine according to claim 1, characterized in that: The conveying device (5) includes a support frame (51) and a conveyor belt (52). A driving wheel (53) and a driven wheel (54) are respectively arranged at both ends of the conveyor belt (52). Guard plates (55) are arranged on both sides of the conveyor belt (52).

3. The automatic discharging device of a vibration grinding machine according to claim 2, characterized in that: When the elevating hopper (2) is completely sleeved with the grinding machine (1), the front arm electric elevating rods (3) and the rear arm electric elevating rods (4) are both in the state of the shortest arm length. A pressure sensor is arranged at the connection between one of the front arm electric elevating rods (3) and the support plate (24).

4. The automatic discharging device of a vibration grinding machine according to claim 3, characterized in that: A rolling limit switch (9) is embedded and fixed on the outer wall of the upper part of the central column (11). The roller of the rolling limit switch (9) is exposed on the outer wall of the central column (11). When the hopper sleeve (21) is sleeved with the central column (11), the inner wall of the hopper sleeve (21) presses the rolling limit switch (9) to close. When the hopper sleeve (21) is separated from the central column (11), the rolling limit switch (9) is disconnected.

5. The automatic discharging device of a vibration grinding machine according to claim 4, characterized in that: A controller is arranged in the grinding machine (1). After grinding is completed, the front arm electric elevating rods (3) and the rear arm electric elevating rods (4) are simultaneously started to rise synchronously, so that the hopper sleeve (21) of the elevating hopper (2) is separated from the central column (11). When the controller receives the disconnection signal of the rolling limit switch (9), it controls to disconnect the front arm electric elevating rods (3) and the rear arm electric elevating rods (4) at the same time, and at the same time, the vibrating grinding machine continues to work, so that the abrasive in the elevating hopper (2) falls off from the filter holes (23) and enters the grinding ring groove (12).

6. The automatic discharging device of a vibration grinding machine according to claim 5, characterized in that: The width of the conveyor belt (52) is greater than the width of the blanking chute opening (25). An optoelectronic emitter (7) is provided at the front end of the baffle plate (55). Optoelectronic receivers (8) are provided at the front ends of the support plates (24) on the left and right sides of the blanking chute opening (25). The optoelectronic emitter (7) and the optoelectronic receivers (8) are horizontally aligned.

7. The automatic discharging device of a vibration grinding machine according to claim 6, characterized in that: The controller collects the pressure values of the pressure sensors in real time, and records the difference between the maximum value and the minimum value of the pressure values as the pressure amplitude. When the pressure amplitude tends to be stable, all the abrasive enters the grinding ring groove (12). At this time, the controller starts the front arm electric lifting rod (3) and the rear arm electric lifting rod (4) to rise synchronously again. When the optoelectronic receiver (8) receives the optoelectronic signal, the height of the blanking chute opening (25) is greater than the height of the conveyor belt (52). At this time, the front arm electric lifting rod (3) stops, and the rear arm electric lifting rod (4) continues to rise to the maximum arm length, so that the lifting hopper (2) tilts towards the conveying device (5) to pour the ground material.

8. The automatic discharging device of a vibration grinding machine according to claim 7, characterized in that: During the process of pouring the material, the grinding machine continues to work. The controller collects the pressure values of the pressure sensors in real time, and records the difference between the maximum value and the minimum value of the pressure values as the pressure amplitude. When the pressure amplitude tends to be stable, all the ground material enters the conveying device (5), and the controller starts the front arm electric lifting rod (3) and the rear arm electric lifting rod (4) to descend to the shortest arm length.

9. The automatic discharging device of a vibration grinding machine according to claim 1, characterized in that: Springs (6) are fixed to the telescopic ends of the front arm electric lifting rod (3) and the rear arm electric lifting rod (4), and are hinged to the support plate (24) through the springs (6).

Images