Constant force ratchet tensioning mechanism for determining the tension of a strap

Abstract

The application discloses a constant force ratchet tightening mechanism for determining the tightening force of a binding belt. The constant force ratchet tightening mechanism is mainly composed of a ratchet tightening mechanism and a constant force slipping mechanism. The ratchet tightening mechanism is connected with the binding belt and has the function of tightening the binding belt. The constant force slipping mechanism is connected with the ratchet tightening mechanism and has the function of slipping with constant force, and provides the tightening torque for the tightening of the binding belt. The application solves the problem that the binding rope belt cannot be pre-tightened quantitatively.

Description

Technical Field

[0001] This invention relates to the field of special airdrop application technology, and in particular to a constant-force ratchet tightening mechanism for determining the tightening force of straps. Background Technology

[0002] Currently, various tethering strap tightening devices use ratchet or threaded mechanisms for tightening. Existing ratchet tighteners have the function of tightening and releasing the tether; the tether is tightened by cranking the handle, and released by the release mechanism on the handle. When securing general goods, tightening is done by the operator's experience and feel, making it impossible to quantify the degree of tightening. When tightening fragile materials, excessive force applied by the operator may damage the materials.

[0003] Existing ratchet tightening mechanisms have the function of tightening the tether, but the tightening force cannot be determined. When the tethered object has strict requirements on the tightening force of the tether, it is difficult to complete the tethering task.

[0004] During a boat airdrop, the mooring straps were connected to important equipment, which placed strict requirements on the mooring tension. Existing tensioners could not meet the mooring tension requirements. Summary of the Invention

[0005] The purpose of this invention is to provide a tether tightening mechanism with a constant force tightening function to meet the tethering requirements during airdrops.

[0006] The technical solution to achieve the purpose of this invention is: a constant force ratchet tightening mechanism for determining the tightening force of the strapping, including a ratchet tightening mechanism and a constant force slip mechanism, wherein the cylindrical part of the strapping clamp above the ratchet tightening mechanism is connected to the circular hole below the constant force slip mechanism.

[0007] Furthermore, the ratchet tightening mechanism consists of a ratchet, a tape clamp, a stop plate, a main body, a stop spring, a cotter pin, and bolts and nuts;

[0008] The main body is a concave shell. The strap clamp is a cylinder with a slit cut along its generatrix, wide enough for the strap to pass through. The strap clamp is fitted into a circular hole on the top of the main body and can rotate around its axis. The ratchet has two semi-circular through holes at its center, corresponding to the cross-section of the strap clamp, and is fitted onto the strap clamp to transmit rotational motion to it. Cotter pins are installed on both sides of the strap clamp to restrict the axial movement of the ratchet. The stop plate is a thin sheet with a U-shaped head, fitted into a rectangular slit running through the middle of the main body, allowing it to move within the slit. The protruding part in the middle of the stop plate mates with the main body's bore shaft to restrict the stop plate's movement. The direction of movement ensures that the stop plate can only move along the centerline. A stop spring is installed at the hole-shaft mating point to keep the stop plate at one end when it is not under force. The outermost part of the stop plate engages with the ratchet teeth. One side of the ratchet teeth is flat and the other side is curved. When the ratchet rotates in the flat direction, the flat surface engages with the stop plate, and the stop plate is not subjected to axial force. At the same time, the ratchet is also locked and cannot rotate in that direction. When the ratchet rotates in the curved direction, the curved surface of the ratchet teeth engages with the stop plate, and the stop plate is subjected to axial force, which overcomes the axial movement of the stop spring. There is a round hole at the bottom of the main body that runs through both sides for installing bolts and nuts.

[0009] Furthermore, the main body has holes corresponding to the parts for mounting the parts, and there is a round hole on the top of the main body that runs through both sides for mounting the strap clamping block. There is a rectangular slot in the middle that runs through both sides for mounting the stop plate. The bottom surface below the rectangular slot is folded up to form a flat surface for supporting the stop spring. There is a through hole in the middle of the protrusion that can pass through the boss above the stop plate. The main body bolts and nuts are used to mount the tethering strap.

[0010] Furthermore, the constant force slip mechanism consists of a rocker arm, a constant force plate, a handle, a movable plate, a constant force spring, a pull rod, a return spring, transmission gears, a stop shoe, and a shaft;

[0011] The rocker arm is a diamond-shaped thin plate, with two rocker arms symmetrically distributed on the left and right. The rocker arm has holes and slots for installing other parts. There is a circular through hole at the top for installing the handle, and a longitudinal rectangular slot in the middle for installing the movable plate. There are two circular through holes spaced apart in the middle of the rectangular slot for installing the retaining plate. There is an oblong through hole below the rectangular slot for installing the shaft, and a circular through hole at the bottom for cooperating with the tape winding clamp.

[0012] Furthermore, the handle is a set of sleeve bolts connected above the two rocker arms, and also serves as a part to be held during operation; the movable plate is a butterfly-shaped thin plate with a through hole in the center. The movable plate is assembled between the two rocker arms, and the protruding parts on both sides cooperate with the rectangular grooves on the rocker arms, allowing it to move along the grooves.

[0013] Furthermore, the retaining plate is a triangular thin plate with a base greater than the width of the movable plate and a height less than the width of the movable plate. It has a through hole in the middle and is assembled onto the rocker arm by rivets. The retaining plate can rotate around the hole. When the base of the triangle is parallel to the movable plate, it can block the movement of the movable plate. When the height of the triangle is parallel to the movable plate, the movable plate can move through.

[0014] Furthermore, the stop shoe is a U-shaped part with a threaded hole on the upper surface and trapezoidal grooves on both sides. The grooves contain through holes and are mounted on the rocker arm below it via a shaft, parallel to the movable plate. The transmission gear is a conical plate-shaped part with through holes at its large end. It is mounted on both sides of the shaft, its plane fitting the groove surface of the stop shoe. Above the gear is a rectangular protrusion with through holes, through which a return spring can pass. The pull rod is a set of screw and nut. The pull rod passes through the center hole of the movable plate and connects to the threaded hole of the stop shoe, allowing the stop shoe to move only along the pull rod's axial direction. The constant force spring is a cylindrical compression spring installed between the movable plate and the stop shoe. Its axis mates with the pull rod's axis. By adjusting the pull rod nut, the constant force spring can be compressed. Then, by adjusting the constant force plate so that its bottom edge mates with the movable plate, and loosening the pull rod nut, the pressure of the constant force spring is transmitted to the rocker arm through the constant force plate, pressing the stop shoe under the rocker arm.

[0015] The return spring is a torsion spring with its axis matching the axis of the pull rod. The spring wire passes through a small hole on the transmission gear, so that the transmission gear is always biased to one side when there is no load. The rocker arm is mounted on the strapping clamp of the ratchet tightening mechanism and can rotate around the strapping clamp.

[0016] Furthermore, the transmission teeth engage with the ratchet. Due to the influence of the retaining shoe groove, the transmission teeth can only transmit load in one direction to the ratchet. The mating surface between the transmission teeth and the ratchet is not perpendicular to the pull rod. The load on the transmission teeth always has a component in the axial direction of the pull rod. When the component is greater than the pressure of the constant force spring, the transmission teeth push the retaining shoe upward and leave the ratchet, no longer transmitting load to the ratchet.

[0017] Compared with the prior art, the present invention has the following significant advantages: (1) It can achieve the tightening function. By shaking the tightener back and forth, the rope is wound into the tightener under the unidirectional rotation of the ratchet to complete the tightening of the rope; (2) It can achieve the constant force slip function. The handle of the tightener is equipped with a spring and a transmission tooth. When the operator tightens the force too much, the spring is compressed and the transmission tooth is disengaged from the ratchet tooth. The ratchet cannot continue to rotate, thus achieving the constant force slip of the handle and preventing the tightening force from being too great and damaging the materials. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the constant force ratchet tightening mechanism of the present invention.

[0019] Figure 2 This is a schematic diagram of the ratchet tightening mechanism.

[0020] Figure 3 This is a schematic diagram of a constant force slip mechanism. Detailed Implementation

[0021] This invention is mainly applied in my country's maritime airdrop field to achieve stable mooring of a certain airdrop vessel.

[0022] This invention mainly consists of a ratchet tightening mechanism and a constant-force slip mechanism. The ratchet tightening mechanism is connected to the tethering strap and has the function of tightening the tethering strap. The constant-force slip mechanism is connected to the ratchet tightening mechanism, has the function of constant-force slippage, and provides tightening torque for tightening the tethering strap. This solves the problem of the tethering strap being unable to exert a quantitative preload.

[0023] This invention is similar to the ratchet tightener solution, and achieves the tightening of the tether strap through the principle of unidirectional rotation of the ratchet.

[0024] The constant-force ratchet tightening mechanism of the present invention consists of a ratchet tightening mechanism and a constant-force slip mechanism. The ratchet tightening mechanism comprises a ratchet, a belt clamp, a stop plate, a main body, a stop spring, a cotter pin, bolts, and nuts, and is used to install and tighten the tether belt. The constant-force slip mechanism comprises a rocker arm, a constant-force plate, a handle, a movable plate, a constant-force spring, a pull rod, a return spring, a transmission gear, a stop shoe, and a shaft. By cranking the handle, a tightening torque is transmitted to the ratchet tightening mechanism. When the tightening torque exceeds a specified value, the constant-force spring can no longer press the transmission gear, the transmission gear disengages from the ratchet tightening mechanism, and the ratchet tightening mechanism can no longer tighten the tether belt, thus achieving the purpose of determining the tightening force value.

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] The structure of this constant-force ratchet tightening mechanism is as follows: Figure 1 As shown. The main points are as follows:

[0027] 1) This constant-force ratchet tightening mechanism includes: one ratchet tightening mechanism 1 and one constant-force slip mechanism 2. The cylindrical part winding clamp 4 above the ratchet tightening mechanism 1 is connected to the circular hole below the constant-force slip mechanism 2. Figure 1 As shown.

[0028] 2) The ratchet tightening mechanism consists of a ratchet 3, a belt clamp 4, a stop plate 5, a main body 6, a stop spring 7, a cotter pin 8, and bolts and nuts 9, as follows: Figure 2As shown. The main body 6 is a concave-shaped housing. There are holes corresponding to the parts on the main body 6 for the installation of the parts. There is a round hole at the upper part that penetrates both sides for installing the strap clamping block 4. There is a rectangular slit that penetrates both sides in the middle for installing the stop plate 5. There are round holes at the lower part that penetrate both sides for installing bolts and nuts 9. A plane is folded up from the bottom surface below the rectangular slit for supporting the stop spring 7. There is a through hole in the middle of the protrusion that can pass through the boss above the stop plate 5. The strap clamping block 4 is a cylinder with a slit cut along the generatrix. The width of the slit can pass through the mooring strap. The strap clamping block 4 is assembled in the round hole above the main body 6 and can rotate around the axis. There are 2 semi-circular through holes in the center of the ratchet wheel 3, corresponding to the cross-section of the strap clamping block 4. It is assembled on the strap clamping block and can transmit the rotational movement to the strap clamping block. Split pins are installed on both sides of the strap clamping block 4 to limit the axial movement of the ratchet wheel 3. The stop plate 5 is a thin sheet with a shape like the Chinese character 'xue'. It is assembled in the slit of the main body 6 and can move in the slit. The middle protruding part of the stop plate 5 is in shaft-hole fit with the main body 6, restricting the movement direction of the stop plate 5 so that the stop plate 5 can only move along the center line. A stop spring 7 is installed at the shaft-hole fit part, making the stop plate 5 always stay at one end when not under force. The outermost side of the stop plate 5 is in fit with the ratchet teeth. One side of the ratchet teeth of the ratchet wheel 3 is a plane and the other side is a curved surface. When the ratchet wheel 3 rotates in the direction of the plane, the plane is in fit with the stop plate 5, and the stop plate is not subject to axial force. At the same time, the ratchet wheel 3 is also locked and cannot rotate in this direction. When the ratchet rotates in the direction of the curved surface, the curved surface of the ratchet teeth is in fit with the stop plate, and there is an axial component in the force on the stop plate. The stop plate 5 overcomes the stop spring 7 and moves axially. Bolts and nuts 9 are used for installing the mooring strap.

[0029] 3) The constant-force slippage mechanism consists of a rocker arm 10, a constant-force piece 11, a handle 12, a movable plate 13, a constant-force spring 14, a pull rod 15, a return spring 16, a transmission gear 17, a retaining tile 18, and a shaft 19, as Figure 3As shown. The rocker arms 10 are rhomboid thin plates, with two symmetrically distributed on the left and right sides. Each rocker arm 10 has holes and slots for mounting other parts. A circular through-hole at the top is for mounting the handle 12, and a longitudinal rectangular slot in the middle is for mounting the movable plate 13. Two spaced-apart circular through-holes in the middle of the rectangular slot are for mounting the retaining plate 11. An oblong through-hole below the rectangular slot is for mounting the shaft 19, and a circular through-hole at the bottom mates with the tape winding clamp 4. The handle 12 is a set of sleeve bolts connecting the two rocker arms and also serving as a hand grip during operation. The movable plate 13 is a butterfly-shaped thin plate with a central through-hole. The movable plate is assembled between the two rocker arms 10, and its protruding parts on both sides mate with the rectangular slots on the rocker arms 10, allowing it to move along the slots. The retaining plate 11 is a triangular thin plate with a base wider than the width of the movable plate 13 and a height smaller than the width of the movable plate 13. It has a through hole in the center and is riveted to the rocker arm 10. The retaining plate 11 can rotate around the hole. When the base of the triangle is parallel to the movable plate 13, it can block the movement of the movable plate 13; when the height of the triangle is parallel to the movable plate 13, the movable plate 13 can move through. The stop plate 18 is a U-shaped part with a threaded hole on its upper surface and trapezoidal grooves on both sides. The grooves have through holes and are mounted below the rocker arm 10 via a shaft 19, parallel to the movable plate 13. The transmission gear 17 is a conical plate-shaped part with a through hole at its large end. It is mounted on both sides of the shaft 19, its plane fitting the groove surface of the stop plate 18. A rectangular protrusion with a through hole passes through the protrusion, allowing the return spring to pass through. The pull rod 15 is a set of screw and nut. The pull rod passes through the central hole of the movable plate 13 and connects to the threaded hole of the stop plate 18, allowing the stop plate 18 to move only along the axial direction of the pull rod. The constant force spring 14 is a cylindrical compression spring installed between the movable plate 13 and the stop plate 18. Its axis mates with the axis of the pull rod. By adjusting the pull rod nut, the constant force spring 14 can be compressed. Then, the constant force plate 11 is adjusted so that its bottom edge mates with the movable plate, and the pull rod nut is loosened. The pressure of the constant force spring 14 is then transmitted to the rocker arm 10 through the constant force plate 11, pressing the stop plate 18 under the rocker arm 10. The return spring 16 is a torsion spring with its axis mates with the axis of the pull rod 15. The spring wire passes through a small hole on the transmission gear 17, so that the transmission gear 17 is always biased to one side when not under load. The rocker arm 10 is mounted on the strap clamp 4 of the ratchet tightening mechanism 1 and can rotate around the strap clamp. The transmission tooth 17 engages with the ratchet. The transmission tooth is affected by the groove of the retaining shoe 18 and can only transmit load in one direction to the ratchet 3. The engagement surface of the transmission tooth and the ratchet is not perpendicular to the pull rod. The load on the transmission tooth 17 always has a component of the pull rod axis. When the component is greater than the pressure of the constant force spring 14, the transmission tooth pushes the retaining shoe to move upward and leaves the ratchet 3 and no longer transmits load to the ratchet.

[0030] This constant-force ratchet tightening structure is as follows: Figure 1 As shown, the main working process is as follows:

[0031] 1) Rotate the pull rod nut to compress the constant force spring to below the constant force plate, rotate the constant force plate and loosen the pull rod nut so that the constant force plate is subjected to the pressure of the constant force spring.

[0032] 2) Connect the closed loop end of the tether strap to the bolt of the ratchet tightening mechanism;

[0033] 3) Insert the free end of the tether into the gap of the strap clamp and pull the tether to initially tighten it;

[0034] 4) Hold the handle and shake the rocker arm until the constant force release mechanism slips out, which completes the constant force tightening.

[0035] Through prototype testing, this invention has achieved a controlled preload tightening of the tether strap during tightening, thus fulfilling the design objective.

Claims

1. A constant-force ratchet tightening mechanism for determining the tightening force of a strapping band, characterized in that: It includes a ratchet tightening mechanism (1) and a fixed force slip mechanism (2). The cylindrical part winding clamp (4) above the ratchet tightening mechanism (1) is connected to the circular hole below the fixed force slip mechanism (2). The constant force slip mechanism (2) consists of a rocker arm (10), a constant force plate (11), a handle (12), a movable plate (13), a constant force spring (14), a pull rod (15), a return spring (16), a transmission gear (17), a stop shoe (18), and a shaft (19); The rocker arm (10) is a diamond-shaped thin plate. Two rocker arms (10) are symmetrically distributed on the left and right. There is a circular through hole on the top of the rocker arm (10) for installing the handle (12). There is a longitudinal rectangular groove in the middle for installing the movable plate (13). There are two circular through holes spaced apart in the middle of the rectangular groove for installing the force plate (11). There is an oblong through hole below the rectangular groove for installing the shaft (19). There is a circular through hole at the bottom for cooperating with the tape clamp (4). The stop plate (18) is a U-shaped part with a threaded hole on the upper surface and trapezoidal grooves on both sides. The grooves have through holes and are mounted below the rocker arm (10) via the shaft (19), parallel to the movable plate (13). The transmission gear (17) is a conical plate-shaped part with through holes at the large end of the teeth. It is mounted on both sides of the shaft (19) and its plane fits against the groove surface of the stop plate (18). Above the teeth of the transmission gear (17) is a rectangular protrusion with through holes, through which the return spring (16) can pass. The pull rod (15) is a set of screw and nut. The pull rod (15) passes through the center hole of the movable plate (13). The threaded hole of the retaining plate (18) is connected to the retaining plate (18), so that the retaining plate (18) can only move along the axial direction of the pull rod (15); the constant force spring (14) is a cylindrical spring compression spring, which is installed between the movable plate (13) and the retaining plate (18). The axis of the constant force spring (14) is matched with the axis of the pull rod (15). By adjusting the pull rod nut, the constant force spring (14) can be compressed. Then, the constant force plate (11) is adjusted so that the bottom edge of the constant force plate (11) is matched with the movable plate (13), and the pull rod nut is loosened. The pressure of the constant force spring (14) is transmitted to the rocker arm (10) through the constant force plate (11), pressing the retaining plate (18) under the rocker arm (10); The return spring (16) is a torsion spring. The axis of the return spring (16) is matched with the axis of the pull rod (15). The spring wire passes through the small hole on the transmission tooth (17), so that the transmission tooth (17) is always biased to one side when it is not under load. The rocker arm (10) is mounted on the tape clamp (4) of the ratchet tightening mechanism (1) and can rotate around the tape clamp (4).

2. The constant-force ratchet tightening mechanism for determining the strap tightening force according to claim 1, characterized in that: The ratchet tightening mechanism (1) consists of a ratchet (3), a belt clamp (4), a stop plate (5), a main body (6), a stop spring (7), a cotter pin (8), and bolts and nuts (9); The main body (6) is a concave shell. The tape clamp (4) is a cylinder with a slit cut along the generatrix, the slit width of which can pass through the tethering strap. The tape clamp (4) is fitted into a circular hole above the main body (6) and can rotate around the axis. The ratchet (3) has two semi-circular through holes in the center, corresponding to the cross-section of the tape clamp (4). It is fitted onto the tape clamp (4) and can transmit rotational motion to the tape clamp (4). Cotter pins (8) are installed on both sides of the tape clamp (4) to restrict the axial movement of the ratchet (3). The stop plate (5) is a thin sheet with a slit in the middle of the main body (6) that runs through both sides. It can move in the slit. The protruding part in the middle of the stop plate (5) cooperates with the hole shaft of the main body (6) to restrict the movement of the stop plate (5). The direction of movement is such that the stop plate (5) can only move along the center line. A stop spring (7) is installed at the hole-shaft mating point so that the stop plate (5) always stays at one end when it is not under force. The outermost part of the stop plate (5) is in contact with the ratchet (3) teeth. One side of the ratchet (3) teeth is a plane and the other side is a curved surface. When the ratchet (3) rotates in the plane direction, the plane is in contact with the stop plate (5) and the stop plate (5) is not under axial force. At the same time, the ratchet (3) is also stuck and cannot rotate in the plane direction. When the ratchet (3) rotates in the curved surface direction, the curved surface of the ratchet teeth is in contact with the stop plate (5) and the stop plate (5) is under force with an axial component. The stop plate (5) moves axially against the stop spring (7). There is a round hole at the bottom of the main body (6) that runs through both sides for installing bolts and nuts (9).

3. The constant-force ratchet tightening mechanism for determining the strap tightening force according to claim 2, characterized in that: The main body (6) has a round hole on the top of both sides for installing the tape clamp (4), and a rectangular slot in the middle for installing the stop plate (5). The bottom surface below the rectangular slot is folded up to form a flat surface for supporting the stop spring (7). The bolts and nuts (9) on the main body (6) are used to install the tethering strap.

4. The constant-force ratchet tightening mechanism for determining the strap tightening force according to claim 1, characterized in that: The handle (12) is a set of sleeve bolts connected above the two rocker arms (10) and also serves as a part to hold during operation; the movable plate (13) is a butterfly-shaped thin plate with a through hole in the center. The movable plate (13) is assembled between the two rocker arms (10), and the protruding parts on both sides cooperate with the rectangular grooves on the rocker arms (10) and can move along the grooves.

5. The constant-force ratchet tightening mechanism for determining the strap tightening force according to claim 1, characterized in that: The fixed plate (11) is a triangular thin plate with a base greater than the width of the movable plate (13) and a height less than the width of the movable plate (13). It has a through hole in the middle and is assembled on the rocker arm (10) by rivets. The fixed plate (11) can rotate around the hole. When the base of the triangle is parallel to the movable plate (13), it can block the movement of the movable plate (13). When the height of the triangle is parallel to the movable plate (13), the movable plate (13) can move through.

6. The constant-force ratchet tightening mechanism for determining the strap tightening force according to claim 1, characterized in that: The transmission tooth (17) engages with the ratchet (3). Due to the influence of the groove of the retaining shoe (18), the transmission tooth (17) can only transmit a load in one direction to the ratchet (3). The mating surface of the transmission tooth (17) and the ratchet (3) is not perpendicular to the pull rod (15). The load on the transmission tooth (17) always has a component of the pull rod axis. When the component is greater than the pressure of the constant force spring (14), the transmission tooth (17) pushes the retaining shoe (18) to move upward and leaves the ratchet (3) and no longer transmits the load to the ratchet (3).

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