A distractor

Abstract

The utility model discloses a tractor, including fixed frame, the fixed frame inside slide installation has the swing block, and the swing block middle part is provided with the long pinhole, and the upper side and the downside of long pinhole are provided with first tooth structure and second tooth structure respectively, and the fixed frame is rotatoryly installed with the pivot, and the pivot passes through the long pinhole, and the pivot is installed with the swing gear in the long pinhole, when the swing block reciprocating swing, swing gear is engaged with first tooth structure, second tooth structure respectively, and the both ends of fixed frame are installed with push and pull oil cylinder respectively, and the piston rod of both sides push and pull oil cylinder is connected at the both ends of swing block respectively, and the fixed frame still is installed with hand -operated pressure supply device, and hand -operated pressure supply device is connected with the rodless chamber of both sides push and pull oil cylinder through control pipeline respectively to drive the piston rod of both sides push and pull oil cylinder interlocking telescoping, the one end of pivot is installed with the runner outside fixed frame. Tractor passes through hydraulic drive, has greater traction, to satisfy heavy -duty traction demand.

Description

Technical Field

[0001] This utility model relates to the field of traction device technology, and in particular to a traction device. Background Technology

[0002] In industrial production, mining areas, and emergency rescue scenarios, traction equipment is a core tool for material transfer, equipment maintenance, and pipeline upkeep. Its reliability and adaptability directly affect operational efficiency and safety. Current mainstream traction methods are limited by factors such as power source and structural design, making it difficult to meet the diverse needs of complex scenarios.

[0003] Existing electric and hydraulic traction equipment mostly rely on external power or large power units for operation. In remote areas without power grid coverage, temporary maintenance sites, or power outage emergency scenarios, the equipment cannot start, directly causing the interruption of traction operations. Manual traction tools developed for scenarios without power, such as hand-cranked winches and chain-type traction devices, although requiring no external power, are limited by structural strength and transmission efficiency, resulting in insufficient traction force. Most manual tools have a maximum traction force of less than 1 ton, which cannot meet the heavy load requirements such as equipment dragging and workpiece stretching. For example, a commonly used traction device, such as the self-locking hand-cranked winch for a small crane disclosed in CN212151427U, includes a base plate and side plates on both sides of the base plate. A first fixed shaft and a second fixed shaft are provided between the side plates. A winding drum is rotatably connected to the second fixed shaft. A first movable shaft is also rotatably connected between the side plates. At least one end of the first movable shaft extends out of the side plate and has a rotating arm on it. A rotating handle is provided on the rotating arm. A gear one is provided on the end face of the winding drum. A gear two meshing with gear one is provided on the first movable shaft. A rope with a locking hook connected to its end is wound on the winding drum. Its advantages are: convenient cable winding, prevention of hook drooping, and that the rope does not slacken or the hook does not droop during equipment movement or vibration, making it flexible and convenient to use; its disadvantages are: low traction force, unable to meet heavy load requirements such as equipment dragging and workpiece stretching. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a traction device with greater traction force to meet the needs of heavy-load traction.

[0005] To achieve the above objectives, this application provides a traction device, including a fixed frame, a swing block slidably mounted within the fixed frame, an elongated hole in the center of the swing block, a first tooth structure and a second tooth structure respectively provided on the upper and lower sides of the elongated hole, a rotating shaft rotatably mounted on the fixed frame, the rotating shaft passing through the elongated hole, and a swing gear mounted on the rotating shaft within the elongated hole, the swing gear meshing with the first tooth structure and the second tooth structure respectively when the swing block reciprocates, push-pull cylinders respectively mounted at both ends of the fixed frame, the piston rods of the two push-pull cylinders respectively connected to both ends of the swing block, a hand-cranked pressure supply device also mounted on the fixed frame, the hand-cranked pressure supply device being connected to the rodless chambers of the two push-pull cylinders respectively through control pipelines to drive the piston rods of the two push-pull cylinders to alternately extend and retract, and a rotating wheel mounted at the end of the rotating shaft located outside the fixed frame.

[0006] The hand-cranked pressure supply device includes a slotted seat, with pressure pumps installed at both ends of the slotted seat. The pistons of the two pressure pumps extend outwards relative to each other. A hand crank is rotatably mounted on the slotted seat via a swing pin. One end of the hand crank is located inside the slotted seat between the two pressure pumps. The hand crank is connected to the pistons on both sides. The two pressure pumps are connected to the push-pull cylinders on both sides via control pipelines.

[0007] The oscillating gear includes a wheel body, and a section of driving teeth is provided on the outer circumference of the wheel body.

[0008] The swing block has bosses at both ends, and the piston rod has a flange at the end connected to the swing block. The piston rod is fitted with a ring cover, the flange is located inside the ring cover, and the ring cover is screwed and fixed on the flange.

[0009] The swing block has grooves on the upper and lower sides of the elongated hole, and tooth blocks are fixedly installed in the grooves on the upper and lower sides, forming the first tooth structure and the second tooth structure.

[0010] The push-pull cylinder includes a push-pull cylinder body, a first sealing ring installed on the inner wall of the push-pull cylinder body, a piston rod slidably and sealingly installed on the push-pull cylinder body, a first flange provided at one end of the push-pull cylinder body connected to the fixed frame, the first flange being connected to the fixed frame by a first screw; the rodless cavity of the push-pull cylinder body is provided with a first interface, the first interface being connected to the control pipeline.

[0011] The pressure pump includes a pressure cylinder body, in which a piston is slidably and sealingly mounted. The pressure cylinder body is connected to a slotted seat by screws. The rodless chamber of the pressure cylinder body is provided with a second interface, which is connected to a control pipeline.

[0012] The lower end of the hand crank is provided with two sliding holes, and the end of the piston on both sides connected to the hand crank is provided with an ear seat. The ear seat is slidably connected to the corresponding sliding hole through a sliding pin.

[0013] The control pipeline includes a first pipeline connecting two pressure pumps. A first check valve and a second check valve are installed on the first pipeline. The first pipeline is located between the first check valve and the second check valve and connected to the P port of the directional valve. A second pipeline is connected to the upper end of the first pipeline at the first check valve and the second check valve. A third check valve and a fourth check valve are installed on the second pipeline. The second pipeline is located between the third check valve and the fourth check valve and connected to the oil tank. The T port of the directional valve is connected to the oil tank. The A port of the directional valve is connected to the rodless chamber of one push-pull cylinder through the fourth pipeline. The B port of the directional valve is connected to the rodless chamber of the other push-pull cylinder through the fifth pipeline.

[0014] A one-way limiting device is installed at the other end of the rotating shaft outside the fixed frame. The one-way limiting device includes a ratchet and a pawl. The ratchet is fixedly installed on the rotating shaft. One end of the pawl is hinged to the fixed frame by a fixing pin, and the hook at the other end is used to cooperate with the ratchet for limiting. A fixed seat is also installed on the fixed frame. The fixed seat is provided with a clearance hole. A pull rod is installed on the pawl. The pull rod passes through the clearance hole. A spring is installed on the pull rod between the fixed frame and the pawl.

[0015] Compared with the prior art, the above-conceptual technical solution conceived in this application has the following beneficial effects: 1. When pressure is supplied to the left-side push-pull cylinder via a hand-cranked pressure supply device, the swing block slides to the right. At this time, the swing gear meshes with the second tooth structure, causing the rotating shaft and wheel to rotate counterclockwise. When the swing block slides to the right to its end, the swing gear meshes with the first tooth structure. When pressure is supplied to the right-side push-pull cylinder via the hand-cranked pressure supply device, the swing block slides to the left. This causes the rotating shaft and wheel to continue rotating counterclockwise. When the swing block slides to the left to its end, the swing gear meshes with the second tooth structure. This cycle repeats, continuously rotating the rotating shaft and wheel to achieve traction. The traction device, through hydraulic transmission, has greater traction force to meet heavy-load traction requirements.

[0016] 2. This utility model uses a hand crank to push and pull the pressure pumps on both sides in sequence. When the piston of one pressure pump is pulled out, the piston of the other pressure pump is pushed back, thereby supplying oil to the two push-pull cylinders alternately through the control pipeline.

[0017] 3. The other end of the rotating shaft of this utility model, located outside the fixed frame, is equipped with a one-way limiting device. The direction of the rotating shaft is controlled by the one-way limiting device to prevent the gear transmission structure from failing during traction, which could lead to the rotating shaft reversing and causing a safety accident. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0019] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0020] Figure 2 for Figure 1 Enlarged structural diagram at point A in the middle.

[0021] Figure 3 This is a schematic diagram of the main structure of this utility model.

[0022] Figure 4 for Figure 2 Schematic diagram of the AA section.

[0023] Figure 5 This is a schematic diagram of the present invention.

[0024] Figure 6 This is a schematic diagram of the swing block of this utility model being pushed to the left.

[0025] Figure 7 This is a schematic diagram of the swing block of this utility model being pushed to the right.

[0026] Figure 8 This is a schematic diagram of the unidirectional limiting device of this utility model.

[0027] Figure Labels Support 1; Fixed frame 10; Swing block 20, elongated hole 21, first tooth structure 22, second tooth structure 23, groove 24, fixing screw 25, boss 26; Shaft 30, oscillating gear 31, wheel body 311, drive gear 312; Push-pull cylinder 40, push-pull cylinder body 41, first sealing ring 411, first flange 412, first screw 413, first interface 414, piston rod 42, flange 421, ring cover 43; Slotted seat 50, swing pin 51; Pressure pump 60, pressure cylinder 61, second port 611, piston 62, lug 63, sliding pin 64; Hand crank 70, sliding hole 71; Rotary wheel 80; One-way limiting device 90, ratchet 91, pawl 92, fixing pin 93, pull rod 94, fixing seat 95, clearance hole 96, spring 97; Control pipeline 100, first pipeline 101, first check valve 102, second check valve 103, second pipeline 104, oil tank 105, third check valve 106, fourth check valve 107, directional valve 108, fourth pipeline 109, fifth pipeline 110. Detailed Implementation

[0028] To more clearly illustrate the purpose, technical solution, and beneficial effects of this application, a further detailed description of this application is provided below in conjunction with illustrations and specific embodiments. It should be noted that the specific embodiments described below are only used to explain the technical content of this application and do not constitute a limitation on the scope of protection of this application.

[0029] Regarding the explanation of terminology: In this application, "and / or" is used to describe the relationship between related objects, covering three possible situations: taking "A and / or B" as an example, it can indicate the situation where only A exists, A and B exist simultaneously, or only B exists; the symbol " / " indicates the "or" relationship between related objects, such as "A / B" which refers to A or B.

[0030] Regarding the description of the embodiments: The terms "exemplary" and "for example" appearing in this application are only used to illustrate the technical solutions through specific examples. It should be particularly emphasized that any implementation method or design scheme marked as "exemplary" or "for example" should not be construed as having an advantage over other solutions. Such expressions are only used to present the technical concepts more intuitively.

[0031] Example 1: See Figure 1-7 This embodiment provides a traction device, including a fixed frame 10. A swing block 20 is slidably installed inside the fixed frame 10. An elongated hole 21 is provided in the middle of the swing block 20. A first tooth structure 22 and a second tooth structure 23 are respectively provided on the upper and lower sides of the elongated hole 21. A rotating shaft 30 is rotatably installed on the fixed frame 10. The rotating shaft 30 passes through the elongated hole 21. A swing gear 31 is installed in the elongated hole 21. When the swing block 20 swings back and forth, the swing gear 31 interacts with the first tooth structure 22 and the second tooth structure 23 respectively. The gear structure 23 meshes, and push-pull cylinders 40 are respectively installed at both ends of the fixed frame 10. The piston rods 42 of the push-pull cylinders 40 on both sides are respectively connected to both ends of the swing block 20. A hand-cranked pressure supply device is also installed on the fixed frame 10. The hand-cranked pressure supply device is connected to the rodless chamber of the push-pull cylinders 40 on both sides through the control pipeline 100 to drive the piston rods 42 of the push-pull cylinders 40 on both sides to extend and retract alternately. A rotating wheel 80 is installed at one end of the rotating shaft 30 outside the fixed frame 10. A traction rope is wound on the rotating wheel 80.

[0032] The traction rope can be made of steel wire rope, see [link / reference] Figure 1 When pressure is supplied to the left-side push-pull cylinder 40 via the hand-cranked pressure supply device, the swing block 2 slides to the right, as... Figure 7 As shown, at this time, the swing gear 31 meshes with the second tooth structure 23, thereby driving the rotating shaft 30 and the rotating wheel 80 to rotate counterclockwise. When the swing block 2 slides to the right to the end, the swing gear 31 meshes with the first tooth structure 22; when pressure is provided to the right-side push-pull cylinder 40 through the hand-cranked pressure supply device, the swing block 2 slides to the left, as shown. Figure 6As shown, at this time, the rotating shaft 30 and the rotating wheel 80 continue to rotate counterclockwise. When the swing block 2 slides to the left to its end, the swing gear 31 meshes with the second tooth structure 23. This process repeats, driving the rotating shaft 30 and the rotating wheel 80 to rotate continuously to achieve traction. The traction device is hydraulically driven and has a greater traction force to meet the needs of heavy-duty traction.

[0033] In this embodiment, see Figure 1 The hand-cranked pressure supply device includes a slotted seat 50, with pressure pumps 60 installed at both ends of the slotted seat 50. The pistons 62 of the two pressure pumps 60 extend outwards from each other. A hand crank 70 is rotatably mounted on the slotted seat 50 via a swing pin 51. One end of the hand crank 70 located inside the slotted seat 50 is positioned between the two pressure pumps 60. The hand crank 70 is connected to the pistons 62 on both sides. The two pressure pumps 60 are connected to the push-pull cylinders 40 on both sides via control pipelines 100.

[0034] By pushing the hand crank 70 left and right, the pressure pumps 60 on both sides are pushed and pulled in turn. When the piston 62 of the pressure pump 60 on one side is pulled out, the piston 62 of the pressure pump 60 on the other side is pushed back, thereby supplying oil to the push-pull cylinders 40 on both sides alternately through the control pipeline 100.

[0035] In this embodiment, see Figure 6 The oscillating gear 31 includes a wheel body 311, and a drive tooth 312 is provided on the outer circumference of the wheel body 311.

[0036] See Figure 2 The swing block 20 has bosses 26 at both ends, and the piston rod 42 has a flange 421 at the end connecting to the swing block 20. A ring cover 43 is fitted onto the piston rod 42, with the flange 421 located inside the ring cover 43, and the ring cover 43 screwed onto the flange 421. This structure achieves the connection between the piston rod 42 and the swing block 20. See Figure 1 The swing block 20 has grooves 24 on the upper and lower sides of the elongated hole 21, respectively. Tooth blocks are fixedly installed in the grooves 24 on both sides, forming a first tooth structure 22 and a second tooth structure 23. This structure enables the installation of the first tooth structure 22 and the second tooth structure 23. In this embodiment, the tooth blocks are installed on the swing block 20 using fixing screws 25.

[0037] See Figure 1The push-pull cylinder 40 includes a push-pull cylinder body 41, a first sealing ring 411 installed on the inner wall of the push-pull cylinder body 41, a piston rod 42 slidably and sealingly installed on the push-pull cylinder body 41, a first flange 412 provided at the end of the push-pull cylinder body 41 connected to the fixed frame 10, the first flange 412 being connected to the fixed frame 10 by a first screw 413; the rodless cavity of the push-pull cylinder body 41 is provided with a first interface 414, the first interface 414 being connected to the control pipeline 100.

[0038] See Figure 1 The pressure pump 60 includes a pressure cylinder 61, in which a piston 62 is slidably and sealingly installed. The pressure cylinder 61 is connected to the slotted seat 50 by screws. The rodless chamber of the pressure cylinder 61 is provided with a second interface 611, which is connected to the control pipeline 100.

[0039] See Figure 1 The lower end of the hand crank 70 is provided with two sliding holes 71. The end of the pistons 62 on both sides that are connected to the hand crank 70 is provided with an ear seat 63. The ear seat 63 is slidably connected to the corresponding sliding hole 71 through a sliding pin 64. Two pressure pumps 60 can be driven by one hand crank 70.

[0040] See Figure 5 The control pipeline 100 includes a first pipeline 101 connecting two pressure pumps 60. A first check valve 102 and a second check valve 103 are installed on the first pipeline 101. The first pipeline 101 is located between the first check valve 102 and the second check valve 103 and is connected to the P port of the reversing valve 108. A second pipeline 104 is connected to the upper end of the first pipeline 101 located between the first check valve 102 and the second check valve 103. A third check valve 106 and a fourth check valve 107 are installed on the second pipeline 104. The second pipeline 104 is located between the third check valve 106 and the fourth check valve 107 and is connected to the oil tank 105. The T port of the reversing valve 108 is connected to the oil tank 105. The A port of the reversing valve 108 is connected to the rodless chamber of one side push-pull cylinder 40 through the fourth pipeline 109. The B port of the reversing valve 108 is connected to the rodless chamber of the other side push-pull cylinder 40 through the fifth pipeline 110. With the above structure, during use, after switching the oil circuit by the reversing valve 108, the oil inlet control of the fourth pipe 109 and the fifth pipe 110 is realized, and oil is alternately supplied to the push-pull oil cylinders 40 on both sides.

[0041] Example 2: Based on Example 1, see Figure 3 , 4 8. A one-way limiting device 90 is installed at the other end of the rotating shaft 30 outside the fixed frame 10. The one-way limiting device 90 controls the direction of the rotating shaft 30 to prevent the gear transmission structure from failing during traction, which could cause the rotating shaft 30 to reverse and result in a safety accident.

[0042] See Figure 8 The one-way limiting device 90 includes a ratchet 91 and a pawl 92. The ratchet 91 is fixedly mounted on the rotating shaft 30. One end of the pawl 92 is hinged to the fixed frame 10 by a fixing pin 93, and the hook at the other end is used to cooperate with the ratchet 91 for limiting. A fixing seat 95 is also mounted on the fixed frame 10. The fixing seat 95 is provided with a clearance hole 96. A pull rod 94 is mounted on the pawl 92. The pull rod 94 passes through the clearance hole 96. A spring 97 is installed on the pull rod 94 between the fixed frame 10 and the pawl 92.

[0043] Figure 8 In the middle, the rotating shaft 30 can be easily rotated counterclockwise. When the rotating shaft 30 needs to be rotated clockwise, the pull rod 94 is lifted to disengage the hook of the pawl 92 from the ratchet 91.

[0044] When the traction device needs to be fixedly installed, a support base 1 is fixedly installed at the bottom of the fixed frame 10, and the device is installed and fixed through the mounting holes at the bottom of the support base 1.

[0045] The working principle or operation process of this utility model: Forward traction drive: see Figure 5 The hand crank 70 is cranked back and forth, which drives the pistons 62 in the pressure pumps 60 on both sides to reciprocate. At this time, one side of the pressure pump 60 draws in oil, and the other side of the pressure pump 60 pressurizes oil. The pressurized hydraulic oil enters the reversing valve 108 through the first pipe 101, and then enters the push-pull cylinder 40 on the left side through the fourth pipe 109. The piston rod 42 of the push-pull cylinder 40 on the left side extends to the right, thereby driving the swing block 20 to slide to the right. The first tooth structure 22 meshes with the swing gear 31, driving the swing gear 31 to rotate, which in turn drives the rotating shaft 30 and the rotating wheel 80 to rotate, thereby pulling the traction rope wrapped on the rotating wheel 80. Reversing Continuous Traction: When the first tooth structure 22 moves to the end of its stroke along with the swing block 20, the swing gear 31 meshes with the second tooth structure 23, reversing the reversing valve 108. The hand crank 70 is rocked in the opposite direction, and the pistons 62 in the pressure pumps 60 on both sides move in the opposite direction. The suction chamber and the pressure chamber of the pressure pumps 60 on both sides switch. The hydraulic oil enters the reversing valve 108 through the first pipe 101, and then enters the push-pull cylinder 40 on the right side through the fifth pipe 110. The piston rod 42 of the push-pull cylinder 40 on the right side extends to the left, thereby driving the swing block 20 to slide to the left. The second tooth structure 23 meshes with the swing gear 31, driving the swing gear 31 to rotate, thereby driving the rotating shaft 30 and the rotating wheel 80 to rotate continuously, pulling the traction rope wrapped on the rotating wheel 80.

[0046] Traction Stop and Reset: After completing the traction operation, stop cranking the hand crank 70. At this time, the ratchet 91 remains stationary under the limiting action of the pawl 92, and the shaft 30 and wheel 80 no longer rotate, preventing the pulled object from retracting. If it is necessary to reset the equipment, lift the pull rod 94 to disengage the hook of the pawl 92 from the ratchet 91, crank the hand crank 70 to reverse the direction of the reversing valve 108, driving the shaft 30 and wheel 80 to rotate in the opposite direction, releasing the traction rope.

[0047] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A traction device, characterized in that: The frame includes a fixed frame (10), in which a swing block (20) is slidably mounted. A long hole (21) is provided in the middle of the swing block (20). A first tooth structure (22) and a second tooth structure (23) are respectively provided on the upper and lower sides of the long hole (21). A rotating shaft (30) is rotatably mounted on the fixed frame (10). The rotating shaft (30) passes through the long hole (21). A swing gear (31) is installed in the long hole (21) on the rotating shaft (30). When the swing block (20) swings back and forth, the swing gear (31) interacts with the first tooth structure (22) and the second tooth structure (23). The second tooth structure (23) meshes, and push-pull cylinders (40) are installed at both ends of the fixed frame (10). The piston rods (42) of the push-pull cylinders (40) on both sides are connected to both ends of the swing block (20). A hand-cranked pressure supply device is also installed on the fixed frame (10). The hand-cranked pressure supply device is connected to the rodless chamber of the push-pull cylinders (40) on both sides through the control pipeline (100) to drive the piston rods (42) of the push-pull cylinders (40) on both sides to alternately extend and retract. A rotating wheel (80) is installed at one end of the rotating shaft (30) outside the fixed frame (10).

2. The traction device according to claim 1, characterized in that: The hand-cranked pressure supply device includes a slotted seat (50), with pressure pumps (60) installed at both ends of the slotted seat (50). The pistons (62) of the two pressure pumps (60) extend outwards from each other. A hand crank (70) is rotatably mounted on the slotted seat (50) via a swing pin (51). One end of the hand crank (70) located inside the slotted seat (50) is located between the two pressure pumps (60). The hand crank (70) is connected to the pistons (62) on both sides respectively. The two pressure pumps (60) are connected to the push-pull cylinders (40) on both sides respectively via control pipelines (100).

3. A traction device according to claim 1, characterized in that: The oscillating gear (31) includes a wheel body (311), and a drive tooth (312) is provided on the outer circumference of the wheel body (311).

4. A traction device according to claim 1, characterized in that: The swing block (20) has bosses (26) at both ends. The piston rod (42) is connected to the swing block (20) at one end with a flange (421). The piston rod (42) is fitted with a ring cover (43). The flange (421) is located inside the ring cover (43), and the ring cover (43) is screwed and fixed on the flange (421).

5. A traction device according to claim 1, characterized in that: The swing block (20) has grooves (24) on the upper and lower sides of the elongated hole (21), and tooth blocks are fixedly installed in the grooves (24) on the upper and lower sides respectively. The tooth blocks on the upper and lower sides form the first tooth structure (22) and the second tooth structure (23).

6. A traction device according to claim 1, characterized in that: The push-pull cylinder (40) includes a push-pull cylinder body (41), a first sealing ring (411) is installed on the inner wall of the push-pull cylinder body (41), a piston rod (42) is slidably and sealingly installed on the push-pull cylinder body (41), a first flange (412) is provided at one end of the push-pull cylinder body (41) connected to the fixed frame (10), and the first flange (412) is connected to the fixed frame (10) by a first screw (413); the rodless cavity of the push-pull cylinder body (41) is provided with a first interface (414), and the first interface (414) is connected to the control pipeline (100).

7. A traction device according to claim 2, characterized in that: The pressure pump (60) includes a pressure cylinder (61), in which a piston (62) is slidably and sealedly installed. The pressure cylinder (61) is connected to the slotted seat (50) by screws. The rodless chamber of the pressure cylinder (61) is provided with a second interface (611), which is connected to the control pipeline (100).

8. A traction device according to claim 2, characterized in that: The lower end of the hand crank (70) is provided with two sliding holes (71), and the end of the piston (62) on both sides connected to the hand crank (70) is provided with an ear seat (63). The ear seat (63) is slidably connected to the corresponding sliding hole (71) through a sliding pin (64).

9. A traction device according to any one of claims 2-8, characterized in that: The control pipeline (100) includes a first pipeline (101) connecting two pressure pumps (60) on both sides. A first check valve (102) and a second check valve (103) are installed on the first pipeline (101). The first pipeline (101) is located between the first check valve (102) and the second check valve (103) and connected to the P port of the reversing valve (108). A second pipeline (104) is connected to the upper end of the first pipeline (101) on the side of the first check valve (102) and the second check valve (103). The first valve is equipped with a third check valve (106) and a fourth check valve (107). The second pipe (104) is located between the third check valve (106) and the fourth check valve (107) and is connected to the oil tank (105). The T port of the reversing valve (108) is connected to the oil tank (105). The A port of the reversing valve (108) is connected to the rodless chamber of the push-pull cylinder (40) on one side through the fourth pipe (109). The B port of the reversing valve (108) is connected to the rodless chamber of the push-pull cylinder (40) on the other side through the fifth pipe (110).

10. A traction device according to claim 1, characterized in that: The other end of the rotating shaft (30) outside the fixed frame (10) is equipped with a one-way limiting device (90); the one-way limiting device (90) includes a ratchet (91) and a pawl (92). The ratchet (91) is fixedly installed on the rotating shaft (30). One end of the pawl (92) is hinged to the fixed frame (10) by a fixing pin (93), and the hook at the other end is used to cooperate with the ratchet (91) for limiting. A fixed seat (95) is also installed on the fixed frame (10). A clearance hole (96) is provided on the fixed seat (95). A pull rod (94) is installed on the pawl (92). The pull rod (94) passes through the clearance hole (96). A spring (97) is installed on the pull rod (94) between the fixed frame (10) and the pawl (92).

Images