Injection molding device for manufacturing communication gateway shell

Abstract

The utility model discloses an injection molding device for manufacturing a communication gateway shell, which comprises a rack, an injection molding pipe is arranged at one end of the rack, an injection molding screw rod is arranged in the injection molding pipe, a first heating cavity is formed in the injection molding pipe, a heating wire is arranged in the first heating cavity, a second heating cavity is formed in the injection molding screw rod, and the second heating cavity is communicated with the injection molding pipe. A heating rod and heat conduction liquid are arranged in the second heating cavity, a first mold and a second mold are arranged at one end of the injection molding pipe, a hydraulic rod is arranged at the other end of the rack, a moving plate is arranged at the movable end of the hydraulic rod, a moving groove is formed in the moving plate, and buffer springs are arranged at the two ends in the moving groove; the other end of each buffer spring is provided with a moving block, one end of each moving block is rotatably connected with a connecting rod, and the other end of each connecting rod is matched with the second mold, the equipment is uniform in heating, stable injection molding of raw materials is guaranteed, damage to the molds is reduced, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of communication equipment production, and more specifically, to an injection molding device for manufacturing a communication gateway shell. Background Art

[0002] Communication gateway is also called network connector or protocol converter. It can interconnect multiple computers or related equipment and perform conversion tasks. It is commonly found in computer rooms, offices and other spaces with many communication equipment. It is an indispensable and important device in communication equipment. Common gateways are made of plastic shell to save resources while ensuring working effect.

[0003] When common injection molding equipment is performing gateway shell injection molding, the injection molding raw material is passed into the mold from the injection molding tube. When the raw material passes through the injection molding tube, the common injection molding tube will be heated by an externally arranged heating wire to keep the raw material in the injection molding tube at a temperature. However, the heating wire of the general structure can only be arranged around the outer end of the injection molding tube, so that the equipment transfers heat from the inner wall of the injection molding tube to the raw material in the inner outer layer, and the raw material in the inner layer cannot be directly heated and needs to receive the heat transferred by the outer layer raw material. Therefore, the heating cannot be carried out uniformly, and the insulation effect needs to be improved; moreover, when performing injection molding, common injection molding equipment will use hydraulic equipment to push one part of the mold to contact another part, Sufficient pressure is applied to ensure full fit between the molds. When the molds are in contact and fit, the greater pressure will produce a certain impact and cause certain wear to the mold. After long-term use, the mold is easily damaged, affecting the injection molding accuracy, and may even become unusable. In addition, common injection molds are equipped with cooling equipment to help the raw materials to be shaped into a shell. However, the temperature for shaping the raw materials varies depending on the material, and the temperature for shaping most raw materials is at a relatively high level. When the injection molding is just completed, the workers cannot touch it directly. The shell needs to be naturally cooled to a suitable temperature before the workers can touch it freely and perform subsequent operations. Therefore, the work efficiency is not high. Utility Model Content

[0004] 1. Technical issues to be resolved

[0005] In view of the problems existing in the prior art, the utility model provides an injection molding device for manufacturing a communication gateway housing, so as to solve the technical problem that the common injection molding equipment mentioned in the background technology has limited use effect.

[0006] (II) Technical solution

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: an injection molding device for manufacturing a communication gateway shell, comprising a frame, an injection molding tube is provided at one end of the frame, an injection molding screw is provided in the injection molding tube, a first heating cavity is opened in the injection molding tube, a heating wire is provided in the first heating cavity, the heating wire is arranged around the injection molding tube, a second heating cavity is opened in the injection molding screw, a heating rod and a heat transfer liquid are provided in the second heating cavity;

[0008] A first mold and a second mold are provided at one end of the injection molding tube, and the first mold cooperates with the injection molding tube. A hydraulic rod is provided at the other end of the frame, and a movable plate is provided at the movable end of the hydraulic rod. A movable groove is provided on the movable plate, and buffer springs are provided at both ends of the movable groove. The other ends of the two groups of buffer springs are provided with moving blocks, and one end of the moving block is rotatably connected with a connecting rod, and an installation shaft is provided between the connecting rods. The two groups of connecting rods are cooperated through the installation shaft, and the other end of the connecting rod cooperates with the second mold.

[0009] The utility model is further configured that a guide plate is provided at the lower end of the frame, and a cooling box is provided at the lower end of the guide plate to provide a cooling effect.

[0010] The utility model is further configured that a driving shaft is provided at one end of the frame, a supporting shaft is provided on the cooling box and the frame, a conveyor belt is provided on the supporting shaft and the driving shaft, and the conveyor belt cooperates with the supporting shaft and the driving shaft to facilitate the removal of the shell from the cooling box.

[0011] The utility model is further configured that one end of the injection molding tube is rotatably connected with a rotating shaft, the injection molding screw is connected to the rotating shaft, a bearing ring is provided in the rotating shaft, and the heating rod cooperates with the bearing ring to ensure stable cooperation between the injection molding screw and the injection molding tube.

[0012] The utility model is further configured that a driving motor is provided at one end of the frame, a driving wheel is provided at the output end of the driving motor, a driven wheel is provided on the rotating shaft, and the driving wheel cooperates with the driven wheel to provide power to the injection screw.

[0013] The utility model is further configured such that a sliding groove is provided on the second mold, sliding blocks are slidably connected at both ends of the sliding groove, and the sliding blocks are rotatably connected to the connecting rod, so that the connecting rod and the second mold can be stably matched.

[0014] The utility model is further configured that a first guide rod is provided in the moving groove, the first guide rod is slidably matched with the moving block, and a second guide rod is provided in the sliding groove, the second guide rod is slidably matched with the sliding block, so that the moving block and the sliding block can move stably.

[0015] The utility model is further configured such that support frames are provided at both ends of the second mold, support wheels are rotatably connected to the lower ends of the support frames, guide grooves are opened on the frame, and the guide grooves cooperate with the support wheels to ensure stable movement of the second mold.

[0016] (III) Beneficial effects

[0017] Compared with the prior art, the utility model provides an injection molding device for manufacturing a communication gateway housing, which has the following beneficial effects:

[0018] 1. The injection molding tube and the injection molding screw are combined to form a feeding device, and the inner wall of the injection molding tube is heated by the first heating chamber and the heating wire to heat the internal raw materials. The second heating chamber provides space, and the injection molding screw is heated by the heating rod and the heat transfer liquid. The raw materials are heated by the injection molding screw, so that the raw materials in the injection molding tube are heated at both ends at the same time, so that the heating is carried out evenly and the heating effect of the raw materials is guaranteed.

[0019] 2. Injection molding is performed by cooperating with the first mold and the second mold, and the hydraulic rod provides power to push the second mold to cooperate with the first mold. The movable plate, movable groove, movable block, connecting rod, sliding groove and sliding block are coordinated to make the position between the hydraulic rod and the second mold change. The buffer spring provides a buffer effect. When the hydraulic rod pushes the second mold to contact the first mold, the buffer spring can absorb the impact force. While ensuring stable contact, it reduces the loss of the mold and increases the service life of the equipment.

[0020] 3. Guided by the guide plate and picked up by the cooling box, the shell after injection molding falls from the rack into the cooling box. The shell is cooled for the second time by the cold water in the cooling box, so that the temperature of the gateway shell is reduced to the normal temperature, which is convenient for workers to directly touch and take, making it more convenient for workers to get wages and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the front structure of an injection molding device for manufacturing a communication gateway housing in the utility model;

[0022] Figure 2 This is a schematic diagram of the side structure of the injection molding device in the utility model;

[0023] Figure 3 This is a schematic diagram of the coordination structure between the first electric heating cavity and the heating wire in the injection molding tube of the utility model;

[0024] Figure 4 This is a schematic diagram of the matching structure between the injection molding screw, the heating rod and the rotating shaft in the utility model;

[0025] Figure 5This is a schematic diagram of the matching structure between the injection molding screw and the heating rod in the utility model;

[0026] Figure 6 This is a schematic diagram of the matching structure of the movable plate and the second mold in the utility model;

[0027] Figure 7 It is a schematic diagram of the matching structure of the movable plate and the connecting rod in the utility model.

[0028] In the figure: 1. frame; 2. injection molding tube; 3. injection molding screw; 4. first heating chamber; 5. heating wire; 6. second heating chamber; 7. heating rod; 8. heat transfer fluid; 9. first mold; 10. second mold; 11. hydraulic rod; 12. moving plate; 13. moving groove; 14. buffer spring; 15. moving block; 16. connecting rod; 17. mounting shaft; 18. guide plate; 19. cooling box; 20. driving shaft; 21. supporting shaft; 22. conveyor belt; 23. rotating shaft; 24. bearing ring; 25. driving motor; 26. driving wheel; 27. driven wheel; 28. sliding groove; 29. ​​sliding block; 30. first guide rod; 31. second guide rod; 32. support frame; 33. supporting wheel; 34. guide groove. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0031] In the present invention, unless otherwise specified, directions such as "up" and "down" are usually used in reference to the directions shown in the drawings, or in reference to the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "left" and "right" are usually used in reference to the left and right shown in the drawings; "inside" and "outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directions are not used to limit the present invention.

[0032] See also Figure 1-7 An injection molding device for manufacturing a communication gateway shell includes a frame 1, an injection molding tube 2 is provided at one end of the frame 1, an injection molding screw 3 is provided in the injection molding tube 2, a first heating cavity 4 is opened in the injection molding tube 2, a heating wire 5 is provided in the first heating cavity 4, the heating wire 5 is arranged around the injection molding tube 2, a second heating cavity 6 is opened in the injection molding screw 3, a heating rod 7 and a heat transfer liquid 8 are provided in the second heating cavity 6;

[0033] A first mold 9 and a second mold 10 are provided at one end of the injection molding tube 2, and the first mold 9 cooperates with the injection molding tube 2. A hydraulic rod 11 is provided at the other end of the frame 1, and a movable plate 12 is provided at the movable end of the hydraulic rod 11. A movable groove 13 is provided on the movable plate 12, and buffer springs 14 are provided at both ends of the movable groove 13. The other ends of the two groups of buffer springs 14 are provided with moving blocks 15. One end of the moving block 15 is rotatably connected with a connecting rod 16, and a mounting shaft 17 is provided between the connecting rods 16. The two groups of connecting rods 16 are matched through the mounting shaft 17, and the other end of the connecting rod 16 cooperates with the second mold 10.

[0034] In this embodiment, when the device is used, the device is supported by the frame 1 to work, and the plastic raw material is injected into the mold of the communication gateway through the cooperation of the injection molding screw 3 and the injection molding tube 2. When the plastic raw material moves in the injection molding tube 2, the heating wire 5 in the first heating chamber 4 works to provide heat, heats the injection molding tube 2, and transfers the heat to the internal space through the injection molding tube 2 itself. The heating rod 7 also works to generate heat and heats the injection molding screw 3 through the transfer of the heat transfer fluid 8, so that the injection molding screw 3 is heated, and the temperature of the surface of the injection molding screw 3 is increased. Through the cooperation of the inner wall of the injection molding tube 2 and the injection molding screw 3, the outer and inner layers of the plastic raw materials are heated at the same time, so that the heating is carried out evenly.

[0035] More specifically, when the molds are being matched, a thrust is applied by the hydraulic rod 11 to drive the movable plate 12 close to the injection tube 2, and drive the second mold 10 to move toward the first mold 9. After the second mold 10 contacts the second mold 10, the hydraulic rod 11 continues to apply pressure to cause the movable plate 12 to press against the second mold 10. At this time, the movable block 15 will move to both ends in the movable groove 13 to increase the angle between the connecting rods 16, shorten the distance between the movable plate 12 and the second mold 10, and adapt to the change in the position of the movable plate 12. The movable block 15 will apply pressure to the buffer spring 14, and the buffer spring 14 will absorb the impact caused by the extrusion, so that the second mold 10 and the first mold 9 are tightly attached without causing excessive impact to cause damage, so that the first mold 9 and the second mold 10 can be stably matched and the service life is improved.

[0036] See also Figure 1 As an implementation method for secondary cooling: a guide plate 18 is provided at the lower end of the frame 1, and a cooling box 19 is provided at the lower end of the guide plate 18.

[0037] Specifically, after the injection molding operation is completed, the molded shell falls away from the mold and enters the cooling box 19 under the guidance of the guide plate 18. Sufficient cooling water is filled in the cooling box 19 in advance to continuously cool the shell so that the temperature of the finished product drops to a normal stable level for easy manual handling.

[0038] Please refer to Figure 1As a further implementation of the cooling box: a driving shaft 20 is provided at one end of the frame 1, a supporting shaft 21 is provided on the cooling box 19 and the frame 1, a conveyor belt 22 is provided on the supporting shaft 21 and the driving shaft 20, and the conveyor belt 22 cooperates with the supporting shaft 21 and the driving shaft 20.

[0039] Specifically, after the finished shell falls into the cooling box 19, it will contact the conveyor belt 22, and the drive shaft 20 will work to drive the conveyor belt 22 to move. Under the support of the support shaft 21, the conveyor belt 22 will transport the shell, so that the shell will slowly move to the outside while being cooled, which makes it easy to take out the shell and avoid shell accumulation.

[0040] Please refer to Figure 3 As a further implementation of the injection screw: one end of the injection tube 2 is rotatably connected with a rotating shaft 23, the injection screw 3 is connected to the rotating shaft 23, a bearing ring 24 is provided in the rotating shaft 23, and the heating rod 7 cooperates with the bearing ring 24.

[0041] Specifically, the injection molding screw 3 is stably matched with the injection molding tube 2 through the connection of the rotating shaft 23, and when the injection molding screw 3 and the rotating shaft 23 rotate, the rotating shaft 23 cooperates with the heating rod 7 through the bearing ring 24, so that the heating rod 7, the rotating shaft 23 and the injection molding screw 3 can rotate relative to each other, thereby, the heating rod 7 does not need to rotate with the injection molding screw 3, and the connection with the external equipment can be kept stable.

[0042] Please refer to Figure 3 As a further implementation of the injection screw: a driving motor 25 is provided at one end of the frame 1, a driving wheel 26 is provided at the output end of the driving motor 25, a driven wheel 27 is provided on the rotating shaft 23, and the driving wheel 26 cooperates with the driven wheel 27.

[0043] Specifically, the driving motor 25 provides power to drive the driving wheel 26 to rotate, and the driving wheel 26 and the driven wheel 27 cooperate to transmit the power, so that the driven wheel 27 transmits the power to the rotating shaft 23, thereby the driving motor 25 controls the injection screw 3 to rotate through the conduction of the rotating shaft 23.

[0044] Please refer to Figure 6 As a further implementation of the connecting rod: a sliding groove 28 is opened on the second mold 10, and sliding blocks 29 are slidably connected at both ends of the sliding groove 28, and the sliding block 29 is rotatably connected to the connecting rod 16.

[0045] Specifically, the connecting rod 16 is connected to the second mold 10 through the cooperation of the sliding block 29 and the sliding groove 28. When the distance between the movable plate 12 and the second mold 10 changes, the sliding block 29 can move along the sliding groove 28 and rotate with the connecting rod 16, and the amplitude of movement and rotation corresponds to the movable block 15, so that the cooperation between the connecting rod 16 and the second mold 10 remains stable.

[0046] Please refer to Figure 6 and Figure 7 As a further implementation of the moving block: a first guide rod 30 is provided in the moving groove 13, and the first guide rod 30 is slidably matched with the moving block 15; a second guide rod 31 is provided in the sliding groove 28, and the second guide rod 31 is slidably matched with the sliding block 29.

[0047] Specifically, the first guide rod 30 cooperates with the moving block 15 to enable the moving block 15 to move stably in the moving groove 13 , and the second guide rod 31 cooperates with the sliding block 29 to enable the sliding block 29 to move stably in the sliding groove 28 .

[0048] Please refer to Figure 1 and Figure 6 As a further implementation of the second mold: support frames 32 are provided at both ends of the second mold 10, and support wheels 33 are rotatably connected at the lower ends of the support frames 32. Guide grooves 34 are opened on the frame 1, and the guide grooves 34 cooperate with the support wheels 33.

[0049] Specifically, the support frame 32 contacts the frame 1 through the support wheel 33 to support the second mold 10 so that the movement of the second mold 10 remains stable, and the movement of the support wheel 33 is guided by the guide groove 34, thereby limiting the movement of the second mold 10 through the support frame 32.

[0050] In summary, when the overall device is in use or running:

[0051] When the device is in use, the frame 1 is used to support the device to work, and each device is connected to an external power supply device. The driving motor 25 provides power to drive the driving wheel 26 to rotate, and the driving wheel 26 and the driven wheel 27 cooperate to transmit the power, so that the driven wheel 27 transmits the power to the rotating shaft 23, so that the driving motor 25 controls the injection molding screw 3 to rotate through the conduction of the rotating shaft 23, so that the injection molding screw 3 can stably cooperate with the injection molding tube 2, and when the injection molding screw 3 and the rotating shaft 23 rotate, the rotating shaft 23 cooperates with the heating rod 7 through the bearing ring 24, so that the heating rod 7, the rotating shaft 23 and the injection molding screw 3 can rotate relative to each other. Therefore, the heating rod 7 does not need to rotate with the injection molding screw 3, and can maintain a stable connection with external equipment, The injection molding raw material is added to the injection molding tube 2, and the plastic raw material is injected into the mold of the communication gateway through the cooperation of the injection molding screw 3 and the injection molding tube 2. When the plastic raw material moves in the injection molding tube 2, the heating wire 5 in the first heating chamber 4 works to provide heat, and the heat is transferred to the internal space through the inner wall of the injection molding tube 2 to heat the outer layer of the injection molding raw material. The heating rod 7 also works to generate heat, which is transferred through the heat-conducting fluid 8 to heat the injection molding screw 3, so that the injection molding screw 3 is heated, the temperature of the surface of the injection molding screw 3 is increased, and the inner layer of the injection molding raw material is heated. Through the cooperation of the inner wall of the injection molding tube 2 and the injection molding screw 3, the external and internal plastic raw materials are heated at the same time, so that the heating is carried out evenly, ensuring stable and efficient heating.

[0052] More specifically, when the molds are being matched, a thrust is applied by the hydraulic rod 11 to drive the movable plate 12 close to the injection tube 2, and drive the second mold 10 to move toward the first mold 9. After the second mold 10 contacts the second mold 10, the hydraulic rod 11 continues to apply pressure to make the movable plate 12 press against the second mold 10. At this time, the movable block 15 moves toward both ends in the movable groove 13, so that the angle between the connecting rods 16 becomes larger, and the sliding block 29 also moves along the sliding groove 28 and rotates with the connecting rod 16. The amplitude of movement and rotation corresponds to the movable block 15, shortening the distance between the movable plate 12 and the second mold 10, adapting to the change in the position of the movable plate 12, and the first guide rod 30 cooperates with the movable block 15 to make the movable block 15 stable in the movable groove 13. Movement, through the cooperation of the second guide rod 31 and the sliding block 29, the sliding block 29 can move stably in the sliding groove 28. When the moving block 15 moves to both ends, it will exert pressure on the buffer spring 14. The buffer spring 14 shrinks and absorbs the impact caused by the extrusion, so that the second mold 10 and the first mold 9 are tightly attached to each other without causing excessive impact to cause damage, so that the first mold 9 and the second mold 10 can be stably matched, and the service life is improved. In addition, the support frame 32 contacts with the frame 1 through the support wheel 33 to support the second mold 10, so that the movement of the second mold 10 remains stable, and the movement of the support wheel 33 will be guided by the guide groove 34, so that the movement of the second mold 10 is limited by the support frame 32, so that the second mold 10 and the first mold 9 can be stably matched.

[0053] After the injection molding operation is completed, the formed shell falls away from the mold and enters the cooling box 19 under the guidance of the guide plate 18. Sufficient cooling water is filled in the cooling box 19 in advance to continuously cool the shell. After the finished shell falls into the cooling box 19, it will contact the conveyor belt 22, connect the drive shaft 20 with the external power equipment, make the drive shaft 20 work, drive the conveyor belt 22 to move, and with the support of multiple support shafts 21, the conveyor belt 22 transports the shell, so that the shell moves slowly to the outside while cooling, avoiding the accumulation of the shell in the cooling box 19, facilitating the transportation of the cooled shell, facilitating the workers to directly take the gateway shell whose temperature has dropped to a normal stable temperature, and facilitating the workers to organize and carry it.

[0054] In all the schemes mentioned above, the connection between two parts can be selected according to actual conditions by welding, bolt and nut matching connection, bolt or screw connection or other well-known connection methods, which are not described here one by one. In the above, all fixed connections are preferably welded. Although the embodiments of the utility model have been shown and described, it can be understood by ordinary technicians in this field that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the utility model. The scope of the utility model is defined by the attached claims and their equivalents.

Claims

1. An injection molding device for manufacturing a communication gateway housing, comprising a frame (1), characterized in that: An injection molding tube (2) is provided at one end of the frame (1), an injection molding screw (3) is provided in the injection molding tube (2), a first heating chamber (4) is provided in the injection molding tube (2), a heating wire (5) is provided in the first heating chamber (4), the heating wire (5) is arranged around the injection molding tube (2), a second heating chamber (6) is provided in the injection molding screw (3), a heating rod (7) and a heat transfer liquid (8) are provided in the second heating chamber (6); A first mold (9) and a second mold (10) are provided at one end of the injection molding tube (2), and the first mold (9) cooperates with the injection molding tube (2). A hydraulic rod (11) is provided at the other end of the frame (1), and a movable plate (12) is provided at the movable end of the hydraulic rod (11). A movable groove (13) is provided on the movable plate (12), and buffer springs (14) are provided at both ends of the movable groove (13). The other ends of the two groups of buffer springs (14) are provided with moving blocks (15), and one end of the moving block (15) is rotatably connected with a connecting rod (16), and a mounting shaft (17) is provided between the connecting rods (16), and the two groups of connecting rods (16) cooperate through the mounting shaft (17), and the other end of the connecting rod (16) cooperates with the second mold (10).

2. The injection molding device for manufacturing a communication gateway housing according to claim 1 is characterized in that: A guide plate (18) is provided at the lower end of the frame (1), and a cooling box (19) is provided at the lower end of the guide plate (18).

3. The injection molding device for manufacturing a communication gateway housing according to claim 2 is characterized in that: A driving shaft (20) is provided at one end of the frame (1), a supporting shaft (21) is provided on the cooling box (19) and the frame (1), a conveyor belt (22) is provided on the supporting shaft (21) and the driving shaft (20), and the conveyor belt (22) cooperates with the supporting shaft (21) and the driving shaft (20).

4. The injection molding device for manufacturing a communication gateway housing according to claim 1, characterized in that: One end of the injection tube (2) is rotatably connected to a rotating shaft (23), the injection screw (3) is connected to the rotating shaft (23), a bearing ring (24) is provided in the rotating shaft (23), and the heating rod (7) cooperates with the bearing ring (24).

5. The injection molding device for manufacturing a communication gateway housing according to claim 4 is characterized in that: A driving motor (25) is provided at one end of the frame (1), a driving wheel (26) is provided at the output end of the driving motor (25), a driven wheel (27) is provided on the rotating shaft (23), and the driving wheel (26) cooperates with the driven wheel (27).

6. The injection molding device for manufacturing a communication gateway housing according to claim 1, characterized in that: The second mold (10) is provided with a sliding groove (28), and sliding blocks (29) are slidably connected at both ends of the sliding groove (28), and the sliding blocks (29) are rotatably connected to the connecting rod (16).

7. The injection molding device for manufacturing a communication gateway housing according to claim 6 is characterized in that: A first guide rod (30) is provided in the movable groove (13), and the first guide rod (30) is slidably matched with the movable block (15); a second guide rod (31) is provided in the sliding groove (28), and the second guide rod (31) is slidably matched with the sliding block (29).

8. The injection molding device for manufacturing a communication gateway housing according to claim 6, characterized in that: Support frames (32) are provided at both ends of the second mold (10), and support wheels (33) are rotatably connected to the lower ends of the support frames (32). A guide groove (34) is provided on the frame (1), and the guide groove (34) cooperates with the support wheel (33).

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