A tooth surface thin wall structure and its deployment mechanism

Abstract

This invention discloses a toothed thin-walled structure and its unfolding / retracting mechanism, relating to the field of thin-walled support structures and their unfolding / retracting technology. The toothed thin-walled structure is either a single-layer toothed thin-walled structure that can be flattened and bent, or a multi-layer toothed thin-walled structure that can be stacked and bent. The surface of the toothed thin-walled structure has toothed patterns for transmitting interlayer shear force or meshing transmission. The unfolding / retracting mechanism includes a roll assembly, a pressure roller assembly, and an elastic adjustment mechanism integrated together by a frame. The elastic adjustment mechanism is used to maintain the elastic pressing tendency of the roll assembly and the pressure roller assembly. This invention can effectively solve the problems of out-of-plane instability deformation, easy creep deformation, and loosening and jamming during unfolding of existing thin-walled rollable structures.

Description

Technical Field

[0001] This invention relates to the field of thin-walled support structures and their unfolding and retraction technology, specifically to a toothed surface thin-walled structure and its unfolding and retraction mechanism. Background Technology

[0002] Thin-walled support structures that can be stacked and layered, such as bean pod stalks, are thin-walled tubular rod structures made of two "Ω"-shaped bean pods (bean pods) using processes such as symmetrical gluing or welding. When retracted, the bean pod stalks can be flattened and stacked into a layered strip and wound onto a roll; when extended, the section that leaves the roll automatically and elastically returns to a double "Ω"-shaped tubular rod.

[0003] The main problem currently is that during the winding process, since the two pods only meet at their two edge surfaces, interlayer shear forces are generated under bending. Most of this shear force is transmitted laterally and neutralized at the interface, with a small portion offset by friction at the contact surface. Due to the "shear lag effect" of bending, the normal and shear stresses on the cross-section of the pods are unevenly distributed, being greatest at the interface and gradually decreasing away from it. This causes the longitudinal displacement of the pods away from the interface to lag behind, resulting in inconsistent longitudinal deformation. When this inconsistent deformation reaches a certain level, excessive in-plane stress causes local thin-walled instability and outward warping (wrinkling or unevenness) of the pods. Furthermore, the smaller the drum radius, the more turns the pod stalks are wound, and the larger the cross-sectional width, the greater the cumulative warping deformation of the pod stalks in the later stages of winding, making them more prone to delamination and loosening. Other thin-walled support structures that can be stacked into layers also suffer from the same problem.

[0004] To ensure the pod stalks are stacked and rolled tightly, multiple clamping rollers (guide rollers) are needed to apply significant clamping force, or coiling springs are used. However, these measures make the unfolding and winding mechanism overly complex and heavy, reducing its reliability. Furthermore, when the pod stalks used for support are long, larger stalk cross-sectional diameters or wider stacking widths are required to ensure stability and load-bearing capacity. With long lateral shear force transmission paths and large interlayer shear forces, the "shear hysteresis effect" becomes more pronounced, resulting in significant cumulative deformation and warping of the pod stalks. Even with multiple clamping rollers, it is difficult to eliminate wrinkles and unevenness. Excessive clamping and shear forces can easily cause localized plastic deformation or even breakage of the pod stalks, preventing them from straightening or rolling tightly, leading to jamming and other mechanical failures, ultimately causing the task to fail.

[0005] Currently, the unfolding and retraction of thin-walled support structures that can be stacked and layered generally employs a motor-driven drum or pressure roller rotation, with the unfolding and retraction achieved through frictional traction between the drum or pressure roller and the pod stalks. The frictional force is proportional to the contact pressure on the pod stalk surface and the coefficient of friction. However, the greater the contact pressure, the greater the frictional resistance that the pod stalks must overcome during unfolding. Furthermore, the localized warping caused by the aforementioned "shear hysteresis effect," resulting in sections that cannot be stacked, further increases the unfolding or retraction resistance. When the frictional driving force is less than these resistances, the pod stalks will loosen during unfolding. Once the pod stalks loosen and the cavity expands to a certain extent, the motor cannot provide effective traction, ultimately leading to the inability to unfold or retract the pod stalks, causing the mechanism to jam and fail. In addition, due to excessive interlayer shear forces, the required width of the interface between thin-walled support structures is greater; otherwise, they are prone to detachment. Moreover, the longer the storage time during retraction, the greater the material creep deformation, making it impossible to straighten and smooth the structure. Furthermore, due to excessive material stress, fatigue failure occurs during repeated unfolding and retraction processes. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a toothed surface thin-walled structure and its unfolding and retracting mechanism, which can effectively solve the problems of out-of-plane instability and deformation, easy creep deformation, loosening and jamming during unfolding of existing thin-walled rollable structures.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] In a first aspect, embodiments of the present invention provide a toothed surface thin-walled structure, wherein the toothed surface thin-walled structure is a single-layer toothed surface thin-walled structure that can be flattened and bent or a multi-layer toothed surface thin-walled structure that can be stacked and bent, and the surface of the toothed surface thin-walled structure has a toothed structure for transmitting interlayer shear force or meshing transmission.

[0009] As a further implementation, the single-layer toothed thin-walled structure is a C-shaped cross-section rod;

[0010] The multi-layered toothed thin-walled structure is one of the following: toothed pod rod, toothed pod core plate, double C-shaped cross-section rod, herringbone cross-section rod, and Z-shaped cross-section rod.

[0011] As a further implementation, the serrated pod core board includes a first elastic thin plate, a second elastic thin plate, and a hollow elastic sandwich layer disposed between the first elastic thin plate and the second elastic thin plate.

[0012] Under the action of compression force, the first elastic thin plate and the second elastic thin plate can be stacked with the hollow elastic sandwich layer to form a bendable layered structure.

[0013] As a further implementation, the hollow elastic sandwich layer adopts a semi-split toothed pod rod, and the outer surface of the first elastic thin plate and the second elastic thin plate has a toothed section on at least one side, and the rest is a smooth section.

[0014] As a further implementation, the hollow elastic sandwich layer includes a plurality of sequentially arranged toothed pod rods, with at least one side of the first elastic thin plate and the second elastic thin plate having exposed toothed pod rods to form a toothed surface section.

[0015] The outer surfaces of the first and second elastic plates are smooth.

[0016] In a second aspect, embodiments of the present invention also provide a retracting mechanism for a toothed thin-walled structure, including a drum assembly, a pressure roller assembly, and an elastic adjustment mechanism integrated together by a frame, wherein the elastic adjustment mechanism is used to keep the drum assembly and the pressure roller assembly in an elastic pressing tendency;

[0017] The drum assembly includes a drum shaft and a drum rotatably connected to the drum shaft; the pressure wheel assembly includes a pressure wheel shaft and a pressure wheel rotatably connected to the pressure wheel shaft; the surfaces of the drum and the pressure wheel are respectively provided with transmission teeth for meshing with the toothed surface toothed structure.

[0018] As a further implementation, the elastic adjustment mechanism is connected between the reel and the frame, or between the pressure roller and the frame, or between the reel and the pressure roller.

[0019] As a further implementation, the elastic adjustment mechanism is a cantilever elastic support assembly, and both ends of the drum shaft or the pressure wheel shaft are connected to the frame through the cantilever elastic support assembly;

[0020] The cantilevered elastic support assembly includes a cantilever and an elastic hinge assembly. One end of the cantilever is connected to the drum shaft or the pressure wheel shaft, and the other end is hinged to the frame through the elastic hinge assembly.

[0021] As a further implementation, the elastic adjustment mechanism is a scissor-type elastic support assembly, and the two ends of the drum shaft are respectively connected to the corresponding ends of the pressure wheel shaft through the elastic support assembly;

[0022] The scissor-type elastic support assembly includes a pair of scissor blades and an elastic hinge assembly that hinges one end of the pair of scissor blades. The ends of the scissor blades away from the elastic hinge assembly are respectively connected to the end of the drum shaft and the end of the pressure wheel shaft.

[0023] As a further implementation, the elastic hinge assembly includes a hinge shaft, a locking element, and a torsion spring. The hinge shaft is equipped with a torsion spring, which is connected between the cantilever and the frame. The torsion spring stores elastic potential energy for driving the cantilever to continuously roll and press the toothed thin-walled structure with the drum and the pressure wheel.

[0024] As a further implementation, the elastic adjustment mechanism is a C-shaped elastic connecting frame, and the two ends of the drum shaft are respectively connected to the corresponding ends of the pressure wheel shaft through the C-shaped elastic connecting frame.

[0025] As a further implementation, the clamping roller is a single-segment clamping roller or a multi-segment clamping roller, and the clamping roller shaft of the multi-segment clamping roller is connected to the frame with one or more open cantilever elastic support components or cantilever elastic support components for increasing the rolling stiffness.

[0026] The open cantilever elastic support assembly includes an open cantilever, one end of which is connected to the pressure wheel axle, and the other end is connected to the frame via a hinge shaft. A torsion spring is installed on the hinge shaft, and the torsion spring is connected between the open cantilever and the frame.

[0027] As a further implementation, the toothed thin-walled structure is provided with a widened portion on at least one side of the connection end with the drum, and the frame is provided with a blocking block for blocking the widened portion.

[0028] As a further implementation, a drive mechanism is also included, which is used to drive the pressure wheel or the drum to rotate;

[0029] The frame is equipped with at least one stop switch, and the drive mechanism is electrically connected to the stop switch so as to stop when the toothed surface thin-walled structure expands and contracts to its limit position.

[0030] As a further implementation, the deployment and reception mechanism can be a single-unit or dual-unit type;

[0031] When the unfolding and retracting mechanism is a single unit, the toothed thin-walled structure unfolds at the outlet end of the unfolding and retracting mechanism.

[0032] When the unfolding and taking-up mechanism is a dual-machine type, the toothed thin-walled structure is unfolded between the two unfolding and taking-up mechanisms or wound and stored on the rolls within both.

[0033] The beneficial effects of the above embodiments of the present invention are as follows:

[0034] (1) The toothed surface thin-walled structure of the present invention can be a single-layer toothed surface thin-walled structure or a multi-layer toothed surface thin-walled structure. When unfolding and retracting, it is stacked into a thin strip or thin plate under the action of pressing force. The teeth on the inner surface of each layer mesh with each other. When the layered structure is curled or bent, the interlayer misalignment shear is offset by the tooth meshing action, which reduces the interlayer shear misalignment and avoids the shear lag between layers when the layered structure, such as the bean pod stalk, is curled, which leads to the out-of-plane instability of the thin strip and the cumulative deformation and inability to stack. This results in the bean pod stalk not being able to be rolled tightly and the stretching strip getting stuck, thus reducing the mechanical failure rate of the unfolding and retracting mechanism.

[0035] (2) Due to the meshing action of the teeth in each layer of the multi-layer toothed thin-walled structure, the winding and winding mechanism of the present invention will not cause cumulative interlayer deformation or out-of-plane instability during winding and winding. Therefore, it is only necessary to provide a force between the drum and the pressure wheel to flatten the multi-layer toothed thin-walled structure. Due to the meshing action between the teeth on the drum and the pressure wheel and the teeth on the surface of the toothed thin-walled structure, both the multi-layer toothed thin-walled structure and the single-layer toothed thin-walled structure (C-shaped cross-section rod) will be automatically wound tightly on the drum under the driving action, and there will be no delamination or loose winding. Furthermore, the drum and the pressure wheel apply a clamping force to the toothed thin-walled structure through the elastic adjustment mechanism, which can ensure the meshing effect during the winding and winding process. Attached Figure Description

[0036] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0037] Figure 1a This is an exploded view of the toothed bean pod stem in Embodiment 1 of the present invention;

[0038] Figure 1b This is a perspective view of the toothed bean pod stem in Embodiment 1 of the present invention;

[0039] Figure 2a This is a schematic diagram of the assembly of the unfolding and retracting mechanism in Embodiment 2 of the present invention;

[0040] Figure 2b This is an exploded view of the unfolding and retracting mechanism in Embodiment 2 of the present invention;

[0041] Figure 2c This is an assembly diagram of the unwinding and rewinding mechanism in the winding state according to Embodiment 2 of the present invention;

[0042] Figure 2d This is a side view of the unwinding and rewinding mechanism in the winding state according to Embodiment 2 of the present invention;

[0043] Figure 2e This is a schematic diagram of the unfolded state of the unfolding mechanism in Embodiment 2 of the present invention;

[0044] Figure 2f This is an external rendering of the unfolding and retracting mechanism in Embodiment 2 of the present invention;

[0045] Figure 3a This is a partial structural schematic diagram of the unfolding and retracting mechanism in Embodiment 3 of the present invention;

[0046] Figure 3b This is a schematic diagram of the assembly of the unfolding and retracting mechanism in Embodiment 3 of the present invention;

[0047] Figure 4a This is an exploded view of a partial structure of the drive mechanism in Embodiment 4 of the present invention;

[0048] Figure 4b This is an assembly diagram of the drive mechanism in its deployed state according to Embodiment 4 of the present invention;

[0049] Figure 4c This is an assembly diagram of the drive mechanism in the winding state in Embodiment 4 of the present invention;

[0050] Figure 5a This is an exploded view of the elastic adjustment mechanism in Embodiment 5 of the present invention;

[0051] Figure 5b This is an assembly diagram of the elastic adjustment mechanism in Embodiment 5 of the present invention;

[0052] Figure 6a This is an exploded view of the elastic adjustment mechanism in Embodiment Six of the present invention;

[0053] Figure 6b This is an assembly diagram of the elastic adjustment mechanism in Embodiment Six of the present invention;

[0054] Figure 6c This is an assembly diagram of the unfolding and retracting mechanism in Embodiment Six of the present invention;

[0055] Figure 7a This is an exploded view of the elastic adjustment mechanism in Embodiment 7 of the present invention;

[0056] Figure 7b This is an assembly diagram of the elastic adjustment mechanism in Embodiment 7 of the present invention;

[0057] Figure 8a This is a three-dimensional schematic diagram of the C-shaped cross-section rod in its natural state according to Embodiment 8 of the present invention;

[0058] Figure 8b This is a three-dimensional schematic diagram of the human-shaped cross-section rod in its natural state in Embodiment 8 of the present invention;

[0059] Figure 9a This is a schematic diagram of the cooperation between the roll assembly and the pressure roller assembly in Embodiment 9 of the present invention;

[0060] Figure 9b This is a schematic diagram of the toothed surface area unit structure of the pod core plate according to Embodiment 9 of the present invention;

[0061] Figure 9c This is a schematic diagram of the smooth surface area unit structure of the pod core plate according to Embodiment 9 of the present invention;

[0062] Figure 9d This is a schematic diagram of the pressing state of the smooth surface area unit of the pod core plate in Embodiment 9 of the present invention;

[0063] Figure 10a This is an exploded view of the unfolding and retracting mechanism of Embodiment 10 of the present invention;

[0064] Figure 10b This is a schematic diagram of the unfolding and retracting mechanism of Embodiment 10 of the present invention unfolding the pod core plate;

[0065] Figure 10c This is a schematic diagram of the winding mechanism for the bean pod core plate in Embodiment 10 of the present invention;

[0066] Figure 10d This is a side view of the winding mechanism for the bean pod core plate according to Embodiment 10 of the present invention;

[0067] Figure 10e This is a schematic diagram of the pod core board being completely rolled up in the unfolding mechanism according to Embodiment 10 of the present invention;

[0068] Figure 10f This is a schematic diagram of the unfolded state of the pod core plate according to Embodiment 10 of the present invention;

[0069] Figure 10g This is a schematic diagram of the installation of the second elastic support assembly according to Embodiment 10 of the present invention;

[0070] Figure 11a This is a schematic diagram of the coiled structure of the pod core plate according to Embodiment Eleven of the present invention;

[0071] Figure 11b This is a schematic diagram of the pod core board in the winding state according to Embodiment Eleven of the present invention;

[0072] Figure 12a This is a schematic diagram of the unfolded state of the pod core plate in Embodiment Twelve of the present invention;

[0073] Figure 12b This is an exploded view of the drive mechanism of Embodiment Twelve of the present invention;

[0074] Figure 12c This is a schematic diagram of the drive mechanism of Embodiment Twelve of the present invention assembled on the frame;

[0075] Figure 13 This is a side view of the winding mechanism for the bean pod core plate according to Embodiment Thirteen of the present invention;

[0076] Figure 14This is a schematic diagram of the winding mechanism for the pod core plate in Embodiment Fourteen of the present invention.

[0077] Wherein, 1-outer shell; 101-left shell; 102-right shell; 103-top shell; 104-upper limit plate; 105-lower limit plate; 2-frame; 201-first shaft hole group; 202-second shaft hole group; 203-third shaft hole group; 204-motor base; 205-adapter ear; 3-toothed thin-walled structure; 30-toothed pod rod; 301-pod slice; 302-pod rod connecting end; 303-plug; 304-widening part; 31-toothed pod core plate; 310-toothed pod core plate connecting end; 311-first elastic thin plate; 312-second elastic thin plate; 313-half-section toothed pod rod; 32-C-shaped cross-section rod; 33-herringbone cross-section rod; 4-drum assembly; 401-drum shaft; 402-bearing; 403 - Drum connecting end; 404- Drum; 4041- Drum toothed section; 4042- Drum smooth section; 5- Pressure wheel assembly; 501- Pressure wheel shaft; 502- Pressure wheel; 5021- Pressure wheel toothed section; 5022- Pressure wheel smooth section; 6- Elastic adjustment mechanism; 60- Cantilever elastic support assembly; 601- Hinge shaft; 602- Torsion spring; 603- Locking element; 604- Cantilever; 605- Open cantilever; 61- Open cantilever elastic support assembly; 7- Drive mechanism; 701- Drive gear; 702- Drive motor; 8- Stopping block; 9- First stop switch; 10- Second stop switch; 11- C-type elastic connecting frame; 12- Scissor-type elastic support assembly; 1201- Scissor blade; 13- Screw; 14- Screw hole. Detailed Implementation

[0078] Example 1:

[0079] This embodiment provides a thin-walled structure with toothed surfaces, such as Figure 1a and Figure 1b As shown, the toothed thin-walled structure is a toothed pod stem 30, which is a double-layered toothed thin-walled structure.

[0080] Specifically, the toothed pod stem 30 is formed by two thin-shelled pod segments 301 in an "Ω" shape closing towards each other. The connection method of the two side edge joint surfaces can be adhesive or welding. Both the inner and outer surfaces of the pod segments 301 are machined with teeth, where the inner surface teeth are used to transmit interlayer shear force, and the outer surface teeth are used for transmission and clamping. Under the action of the pressing force, the two pod segments 301 overlap along the overlapping surface, and the teeth on their inner surfaces match and mesh with each other.

[0081] To reduce structural weight and bending stiffness after stacking, the toothed thin-walled structure has regular mesh openings on its surface.

[0082] Example 2:

[0083] This embodiment provides an unfolding and retracting mechanism for a toothed surface thin-walled structure, which is particularly suitable for the toothed surface thin-walled structure described in Embodiment 1, such as... Figures 2a-2f As shown, the assembly includes a roll assembly 4, a pressure roller assembly 5, and an elastic adjustment mechanism 6, all integrated and mounted on the frame 2. The roll assembly 4 is used to wind the toothed pod stalks 30, the pressure roller assembly 5 serves as a pressure roller, and the elastic adjustment mechanism 6 is used to maintain the elastic pressing tendency of the roll assembly 4 and the pressure roller assembly 5. The toothed pod stalks 30 are squeezed by the pressure roller assembly 5 and the roll assembly 4 to make the layers mesh, and then wound onto the roll assembly 4.

[0084] like Figure 2b As shown, the roller assembly 4 includes a roller shaft 401 and a roller 404 rotatably connected to the roller shaft 401. The pressure roller assembly 5 includes a pressure roller shaft 501 and a pressure roller 502 rotatably connected to the pressure roller shaft 501. The axis of the pressure roller 502 is parallel to the axis of the roller 404. In this embodiment, the roller 404 and the roller shaft 401 are rotatably connected by a bearing 402. Similarly, a bearing is also installed between the pressure roller 502 and the pressure roller shaft 501.

[0085] Both the drum 404 and the pressure roller 502 have teeth that mesh with the teeth on the surface of the toothed pod rod 30. The tail end of the toothed pod rod 30 is provided with a flattened and stacked pod rod connecting end 302 for connecting with the drum 404. The tail end of the toothed pod rod 30 passes between the pressure roller 502 and the drum 404 and is fixedly wound on the drum 404. In the exit direction, it gradually expands elastically from the flattened and stacked state to a natural tubular shape of a certain height, extending to the head end of the toothed pod rod 30 and is sealed with a plug 303.

[0086] The outer periphery baseline of the cross-section of the drum 404 is an Archimedean spiral unfolded in one rotation (equidistant spiral). A drum connecting end 403 for mounting the pod stem connecting end 302 is provided at the starting region of the spiral unfolded line on its outer periphery. The distance (pitch) between the starting and ending points of the spiral unfolded line is the same as the thickness of the pod stem connecting end 302 or the overlapping thickness of the toothed pod stems 30. The lower surface teeth of the pod stem connecting end 302 engage with the surface teeth of the drum connecting end 403, connecting them by adhesive or mechanical anchoring. At the interface between the two, the upper surface of the pod stem connecting end 302 smoothly and tangentially connects to the outer periphery of the drum 404.

[0087] In this embodiment, the elastic adjustment mechanism 6 is a cantilever elastic support assembly 60. The two ends of the drum shaft 401 are connected to the frame 2 through the cantilever elastic support assembly 60, and the two ends of the pressure wheel shaft 501 are assembled with the second shaft hole group 202 opened on the frame 2.

[0088] like Figures 2b-2e As shown, the cantilevered flexible support assembly 60 includes a cantilever 604 and an elastic hinge assembly. One end of the cantilever 604 is connected to the drum shaft 401, and the other end is hinged to the frame 2 via the elastic hinge assembly. The elastic hinge assembly includes a hinge shaft 601, a locking member 603, and a torsion spring 602 assembled together. One end of the hinge shaft 601 passes through the first shaft hole group 201 opened in the frame 2, and the shaft section of the hinge shaft 601 located in the frame 2 is fitted with the torsion spring 602. One end of the torsion spring 602 is connected to the swing arm 604, and the other end is connected to the frame 2. The torsion spring 602 is restricted to the hinge shaft 601 by the locking member 603. During operation, the swing arm 604 drives the hinge shaft 601 to rotate, and the rotation of the hinge shaft 601 causes the torsion spring 602 to undergo elastic deformation. The torsion spring 602 always acts on the cantilever 604, forcing the drum 404 to always approach the pressure wheel 502, and forcing the gathered toothed pod rod 30 to always be tightly wound on the drum 404.

[0089] In this embodiment, the toothed pattern on the surface of the toothed pod rod 30 is a full toothed structure. Correspondingly, the toothed pattern on the surface of the drum 404 and the pressure wheel 502 corresponds to the toothed pattern on the surface of the toothed pod rod 30. That is, the surfaces of the drum 404 and the pressure wheel 502 are also fully covered with teeth that mesh with and drive the transmission.

[0090] The cross-section of the teeth in the tooth pattern can be trapezoidal, arc-shaped, or other shapes. The pod-shaped 301 material can be made of high-elasticity metal materials such as beryllium copper, nickel-titanium shape memory alloy, and high-strength steel. It can also be made of fiber-reinforced resin composite materials, such as high-strength fiber-reinforced polyurethane, rubber, and polyimide matrix composites made from carbon fiber, glass fiber, basalt fiber, and steel fiber. The thickness of the pod-shaped 301 material can range from 0.01 to 2 mm.

[0091] The frame 2 is externally provided with an outer shell 1 to protect the components mounted on the frame 2. In this embodiment, the frame 2 has an L-shaped cross-section, where the cross-section refers to the vertical section along the length of the toothed pod rod 30. The outer shell 1 includes a left shell 101, a right shell 102, and a top shell 103 that are joined together. The top shell 103 and the top of the frame 2 form an extension and retraction channel for the toothed pod rod 30 to extend and retract. An upper limit plate 104 and a lower limit plate 105 are provided at the front end of the extension and retraction channel. The upper limit plate 104 and the lower limit plate 105 can be assembled with the outer shell 1 or with the frame 2. The upper limit plate 104 and the lower limit plate 105 together form the cross-sectional shape of the toothed pod rod 30, allowing the toothed pod rod 30 to move up and down appropriately at the front end of the extension and retraction channel.

[0092] To prevent the toothed pod stem 30 from being overextended, widening portions 304 are provided on both sides of the pod stem connecting end 302. Correspondingly, blocking blocks 8 are symmetrically installed on both sides of the frame 2. When the toothed pod stem 30 is extended to the final stage, the widening portions 304 leave the outer circumference of the drum 404, and the motion changes from rotation to outward translation. When the widening portions 304 touch the blocking blocks 8, the maximum extension position is reached. The blocking blocks 8 are detachably assembled and disassembled with the screw holes 14 opened on the frame 2 via screws 13.

[0093] The working principle of this embodiment is as follows:

[0094] When the toothed pod stalk 30 needs to be retracted, it drives the drum 404 to perform a winding operation under the inward thrust. Under the combined rolling and meshing action of the drum 404 and the pressure roller 502, the toothed pod stalk 30, initially expanding from a natural tubular shape, sequentially enters the transition zone, the rolling overlap zone, and the winding zone. In both the rolling overlap zone and the winding zone, the teeth on both inner surfaces of the toothed pod stalk 30 are in a meshing state. In the rolling overlap zone, the upper and lower surface teeth of the toothed pod stalk 30 are rolled and meshed with the pressure roller 502 and the drum 404, respectively. In the winding zone, the innermost pod stalk segment meshes with the outer peripheral surface teeth of the drum 404. During continued winding, the lower surface teeth of the pod stalk segment to be wound mesh with the upper surface teeth of the already wound pod stalk segment.

[0095] During the winding process, as the number of winding turns increases, the winding diameter of the toothed pod rod 30 also increases accordingly. Since the drum assembly 4 adopts an elastic swing support installation method, in order to adapt to the increased winding diameter, the drum assembly 4 will swing downward to expand the winding space. During the downward swing, the torsion spring 602 will elastically deform synchronously and continuously provide elastic force to the drum assembly 4, so that the drum assembly 4 maintains the tendency to move closer to the pressure wheel 502, thereby ensuring that the drum 404 and the pressure wheel 502 continuously roll the toothed pod rod 30.

[0096] When the toothed pod rod 30 needs to be unwound, the toothed pod rod 30, under the action of outward tension, drives the drum 404 to rotate and drives the toothed pod rod 30 in the winding area to perform the unwound operation. The unwound operation is the reverse movement of the above winding operation. That is, as the toothed pod rod 30 in the winding area is unwound, the number of turns wound on the drum 404 becomes less and less, and the total outer diameter of the winding also becomes smaller accordingly. The drum assembly 4 swings upward adaptively. At the same time, under the action of the torsional force of the torsion spring 602, the drum 404 and the pressure wheel 502 also maintain a pressing tendency, so that the toothed pod rod 30 in the winding area is always in a meshing and holding state around the drum 404, which helps the pod rod to unfold smoothly and avoids it from stretching and being unable to be unwound normally.

[0097] In this embodiment, due to the meshing action between the toothed pod rod 30 and the drum 404, as long as the drum 404 and the pressure roller 502 provide sufficient pressure on the toothed pod rod 30, no loosening will occur during the winding process. Because the toothed pod rod 30 has teeth, it can be wound tightly without a tension spring, reducing the number of pressure rollers in the pressure mechanism. Both retraction and unfolding operations can be performed manually by pushing and pulling, simplifying the unfolding and retraction mechanism and increasing the reliability of the structure's unfolding and retraction.

[0098] Because the two inner surfaces of the toothed pod rod 30 are in a meshing state in both the flattened overlapping area and the winding section, the interlayer misalignment shear is offset by the tooth meshing effect when the toothed pod rod 30 is curled or bent, reducing interlayer shear misalignment. This meshing effect avoids interlayer shear lag, out-of-plane instability, and banding in the winding area of ​​the pod slices, and avoids mechanical failures such as loosening and jamming during the pod rod retraction and unfolding operations. Because the winding stores elastic potential energy, the pod rod can unfold automatically when the friction is low, without the need for power.

[0099] Example 3:

[0100] This embodiment provides a retractable mechanism with a toothed thin-walled structure, which differs from Embodiment 2 in that: this embodiment is applicable to toothed pod rods 30 with toothed structures only on both sides of the outer surface, while the outer surface of the central region is a smooth section; correspondingly, as... Figure 3a and Figure 3b As shown, the drum 404 and the pressure wheel 502 of the winding and unwinding mechanism are only provided with teeth on both sides for meshing and transmission. The middle part of the drum 404 and the pressure wheel 502 are smooth, that is, the surface of the drum 404 is divided into the drum tooth surface section 4041 and the drum smooth surface section 4042, and the surface of the pressure wheel 502 is divided into the pressure wheel tooth surface section 5021 and the pressure wheel tooth surface section 5022.

[0101] The remaining structure is the same as in Example 2, and will not be described again here.

[0102] Example 4:

[0103] This embodiment provides an unfolding and retracting mechanism for a thin-walled structure with a toothed surface. The difference between this embodiment and Embodiment Two is the addition of a driving mechanism 7, such as... Figures 4a-4c As shown, the drive mechanism 7 is installed at the rear of the pressure wheel assembly 5. The drive mechanism 7 includes a drive motor 702 and a drive gear 701 installed at the output end of the drive motor 702. The drive motor 702 is installed on the frame 2 through the motor base 204. The drive gear 701 meshes with the teeth on the surface of the pressure wheel 502 for transmission.

[0104] During operation, the pressure wheel 502 directly drives the drum 404 to rotate, realizing the winding and unfolding of the toothed pod rod 30. In specific applications, a battery compartment can be formed on the rear side of the motor base 204. In addition, to ensure transmission rigidity, the motor shaft is installed in the third shaft hole group 203 reserved in the frame 2.

[0105] To accurately locate the extreme extension and retraction position of the toothed pod stem 30, this embodiment also includes a touch-sensitive stop switch, such as... Figure 4a and Figure 4b As shown, the blocking block 8 is equipped with a first stop switch 9, and the front end of the frame 2 is equipped with a second stop switch 10. Both the first stop switch 9 and the second stop switch 10 are electrically connected to the drive motor 702. When the widened part 304 touches the blocking block 8, the first stop switch 9 is triggered, causing the drive motor 702 to stop. When the end cap 303 of the toothed pod rod 30 touches the frame 2, the second stop switch 10 is triggered, which also causes the drive motor 702 to stop. This serves to protect the unfolding and retracting mechanism.

[0106] It is understood that in other embodiments, the drive gear 701 may not be provided, and the drum assembly 4 may be driven directly by the drive motor 702.

[0107] The remaining structure is the same as in Example 2, and will not be described again here.

[0108] Example 5:

[0109] This embodiment provides an unfolding and retracting mechanism for a toothed thin-walled structure, which differs from Embodiment 2 in that the installation position of the cantilever elastic support assembly 60 is different.

[0110] like Figure 5a and Figure 5b As shown, both ends of the clamping wheel shaft 501 are connected to the frame 2 via a cantilevered elastic support assembly 60, and both ends of the drum shaft 401 are engaged with shaft holes on the frame 2. Meanwhile, to accommodate the installation of the cantilevered elastic support assembly 60, an adapter lug 205 is integrally provided at the rear of the frame 2.

[0111] The remaining structure is the same as in Example 2, and will not be described again here.

[0112] Example 6:

[0113] This embodiment provides an unfolding and retracting mechanism for a thin-walled toothed surface structure, which differs from Embodiment 2 in that the structure and installation position of the elastic adjustment mechanism 6 are different.

[0114] like Figures 6a-6cAs shown, the elastic adjustment mechanism 6 is a C-shaped elastic connecting frame 11. Both ends of the drum shaft 401 are connected to the corresponding ends of the pressure wheel shaft 501 via the C-shaped elastic connecting frame 11. The drum shaft 401 or the pressure wheel shaft 501 is assembled with the frame 2. The main body of the C-shaped elastic connecting frame 11 has a C-shaped structure, with retaining rings formed at both ends, which are used to fix the drum shaft 401 and the pressure wheel shaft 501.

[0115] During operation, the meshing clamping force of the toothed pod rod 30 comes from the elastic restoring force of the C-type elastic connecting frame 11. When the drum 404 is performing a winding operation, as the number of winding turns increases, the C-type elastic connecting frame 11 elastically opens to meet the need for expanding the winding space; when the drum 404 is performing a rewinding operation, the C-type elastic connecting frame 11 elastically closes.

[0116] The remaining structure is the same as in Example 2, and will not be described again here.

[0117] Example 7:

[0118] This embodiment provides an unfolding and retracting mechanism for a thin-walled structure with a toothed surface. The difference between this mechanism and Embodiment 2 is that the elastic adjustment mechanism 6 is a scissor-type elastic support assembly 12. Figure 7a and Figure 7b As shown, the two ends of the drum shaft 401 are connected to the corresponding ends of the pressure wheel shaft 501 through the scissor-type elastic support assembly 12.

[0119] The scissor-type flexible support assembly 12 includes a pair of scissor blades 1201, which are hinged together by an elastic hinge assembly. The ends of the scissor blades 1201 furthest from the elastic hinge assembly are respectively assembled to the ends of the drum shaft 401 and the pressure wheel shaft 501. Either the pressure wheel shaft 501 or the drum shaft 401 is directly mounted on the frame 2. During operation, the scissor-type flexible support assembly 12 provides elastic clamping force.

[0120] The remaining structure is the same as in Example 2, and will not be described again here.

[0121] It should be noted that the provision of elastic clamping force is not limited to the above method. It can also be achieved by setting a groove on the frame 2, and the shaft of the clamping wheel 502 or the drum 404 slides along the groove under the action of the spring, thereby applying clamping force to the toothed pod rod 30 between the two to realize the winding and unfolding of the toothed pod rod 30.

[0122] Example 8:

[0123] This embodiment provides a toothed surface thin-walled structure, which differs from Embodiment 1 in that the toothed surface thin-walled structure adopts an open cross-section, specifically as follows: Figure 8a The C-shaped cross-section rod 32 shown, or as... Figure 8bThe herringbone section bar 33 shown is composed of two elastic thin plates stacked together in a herringbone shape.

[0124] Each type of rod has a toothed surface, and the rest of the structure is the same as in Example 1, so it will not be described again here.

[0125] Furthermore, the provision of toothed surface thin-walled structures is not limited to the above-mentioned methods, but can also be in the form of double C-shaped cross-section bars, Z-shaped cross-section bars, etc.

[0126] Example 9:

[0127] This embodiment provides a thin-walled structure with toothed surfaces, such as Figures 9b-9d As shown, the toothed thin-walled structure is a stackable and flattenable toothed pod core plate 31. The toothed pod core plate 31 includes a first elastic thin plate 311, a second elastic thin plate 312, and a hollow elastic sandwich layer, with the elastic sandwich layer disposed between the first elastic thin plate 311 and the second elastic thin plate 312. Under the action of the pressing force, the upper and lower elastic thin plates together with the elastic sandwich layer are stacked to form a bendable layered structure. After the pressure is released, the structure returns to its original natural state, i.e., a hollow thin-walled support structure.

[0128] The elastic core layer is composed of at least one of the semi-split serrated pod stem 313 and serrated pod stem 30.

[0129] like Figure 9a As shown, semi-serrated pod stalks 313 with outward openings and arranged in parallel are respectively clamped on both sides between the first elastic thin plate 311 and the second elastic thin plate 312. The cutting surfaces of the semi-serrated pod stalks 313 are aligned and connected with the two sides of the two elastic thin plates. Multiple parallel serrated pod stalks 30 are clamped in the middle area of ​​the two elastic thin plates.

[0130] The inner surfaces of the first elastic thin plate 311 and the second elastic thin plate 312 are processed with toothed structures that match and mesh with the surface teeth of the semi-sectioned toothed pod rod 313 and the toothed pod rod 30. The outer surfaces are processed with toothed structures on both sides to form toothed sections, and the middle section is a smooth section with a flexible layer mounted on it.

[0131] like Figures 9b-9d As shown, in its natural state, the toothed area structural cells and smooth area structural cells of the toothed pod core plate 31 are fixedly connected to the toothed pod rod 30 and the half-sectioned toothed pod rod 313 only in the upper and lower top contact areas, and the connection method is bonding or welding. Other non-connected areas can be opened when unloaded and engaged when subjected to force.

[0132] To prevent the pods from failing to stack due to lateral deformation during flattening and stacking, the center axis distance between adjacent toothed pods 30, and the center axis distance between the half-section of the toothed pod 313 and adjacent toothed pods 30, shall not be less than the flattened width of the pods.

[0133] Example 10:

[0134] This embodiment provides an unfolding and retracting mechanism for a toothed surface thin-walled structure, which is particularly suitable for the toothed surface thin-walled structure described in Embodiment Nine, such as... Figure 9a , Figures 10a-10g As shown, the flattened pod core plate 31 of the serrated pod core plate is connected to the roller connection end 403, and the distance between the starting point and the end point of the spiral unfolding line at the interface is the sum of the thickness of the mounting layer and the serrated pod core plate 31.

[0135] The smooth section of the serrated pod core board 31 is used to attach flexible components such as flexible screens, flexible solar panels, and thin-film antennas, or the panel of the serrated pod core board 31 is designed to be fully serrated to facilitate better bonding with flexible components.

[0136] In this embodiment, the drum 404 and the pressure roller 502 are only provided with teeth on the corresponding areas on both sides of the outer peripheral surface to mesh with the toothed pod core plate 31. The middle part of the drum 404 and the pressure roller 502 are both smooth, that is, the surface of the drum 404 is divided into the drum tooth surface section 4041 and the drum smooth surface section 4042, and the surface of the pressure roller 502 is divided into the pressure roller tooth surface section 5021 and the pressure roller tooth surface section 5022.

[0137] like Figure 10g As shown, in order to increase the clamping rigidity of the long and slender clamping roller 502, an open cantilever elastic support assembly 61 is also connected between the clamping roller 502 and the frame 2. In this embodiment, the clamping roller 502 is divided into two sections, and the clamping roller shaft between the two sections of the clamping roller 502 is provided with an open cantilever elastic support assembly 61, which is connected to the adapter lug 205 at the rear of the frame 2.

[0138] The open-end cantilever elastic support assembly 61 includes a hinge shaft 601, a torsion spring 602, and a locking member 603. It differs from the cantilever elastic support assembly 60 in that it includes an open-end swing arm 605. One end of the open-end swing arm 605 has a through hole. The hinge shaft 601 passes through the adapter ear 205 and the through hole, engaging with the torsion spring 602 and the locking member 603. The locking member 603 connects the adapter ear 205 and the open-end swing arm 605. The other end of the open-end swing arm 605 has a hook structure, which hooks onto the pressure wheel shaft 501.

[0139] Similarly, the drum 404 and the pressure roller 502 unfold and retract the toothed pod core plate 31 based on the meshing and extrusion action. Under the action of the internal shear tooth pattern and the external transmission tooth pattern, the structural composite layer will not have the problem of loosening and delamination, thus achieving the purpose of unfolding and retracting freely. Furthermore, through the cooperation of the smooth surface and tooth surface on the drum 404 and the pressure roller 502, it can be applied to the toothed pod core plate 31 with a larger unfolding area.

[0140] Since the toothed pod rod 30 exhibits air exhaust and intake behavior in its internal cavity during the stacking, winding, and unfolding process, an exhaust hole is provided at the panel or plug 33 below the toothed pod core plate 31. Preferably, the exhaust hole is provided in the toothed pod core plate 31 in the inner section of the shell 1.

[0141] The remaining structure is the same as in Example 2, and will not be described again here.

[0142] Example 11:

[0143] This embodiment provides a toothed thin-walled structure, which differs from Embodiment Nine in that the cross-sectional shape of the toothed pod core plate 31 is different, such as... Figure 11a and 11b As shown, the elastic core layer of the serrated pod core plate 31 is the serrated pod stem 30, and the serrated pod stem 30 located at the edge extends from the side of the first elastic thin plate 311 and the second elastic thin plate 312 to form an exposed area; moreover, the outer surfaces of the first elastic thin plate 311 and the second elastic thin plate 312 are smooth, and the two sides of the first elastic thin plate 311 and the second elastic thin plate 312 are aligned with the central axis of the serrated pod stem 30.

[0144] For the winding and unwinding mechanism of the above-mentioned toothed thin-walled structure, the teeth of the drum 404 and the pressure wheel 502 engage with the exposed teeth of the toothed pod rod 30 for transmission; the rest of the structure is the same as in Embodiment 10, and will not be described again here.

[0145] Example 12:

[0146] This embodiment provides an unfolding and retracting mechanism for a thin-walled structure with a toothed surface. The difference between this embodiment and Embodiment Ten is the addition of a driving mechanism 7, such as... Figures 12a-12c As shown, two sets of drive mechanisms 7 are provided, corresponding to the tooth surface section 5021 of the pressure wheel respectively, and the two drive mechanisms 7 are symmetrically distributed with respect to the vertical line of the axis of the pressure wheel shaft 501.

[0147] The remaining structure is the same as in Example 10, and will not be described again here.

[0148] Example 13:

[0149] This embodiment provides a retractable mechanism with a toothed surface and thin wall structure. The difference between this embodiment and Embodiment 10 is that Embodiment 10 is a single-machine model with a single retractable mechanism, while this embodiment is a dual-machine model with two retractable mechanisms. Figure 13 As shown, the two ends of the serrated pod core plate 31 are respectively connected to the rolls 404 in two opposing unfolding and winding mechanisms. That is, the two unfolding and winding mechanisms share a serrated pod core plate 31. The serrated pod core plate 31 is unfolded between the two mechanisms or wound and stored on the rolls 404 in both.

[0150] The remaining structure is the same as in Example 10, and will not be described again here.

[0151] Example 14:

[0152] This embodiment provides an unfolding and retracting mechanism with a toothed surface thin-walled structure, which differs from Embodiment Ten in that: Figure 14 As shown, the structure of this embodiment is a single-cell toothed pod core structure, that is, only two half-sectioned toothed pod stems 313 with their openings facing outward are sandwiched between the two elastic thin plates, and the toothed pod stems 30 are not sandwiched in the middle area.

[0153] The remaining structure is the same as in Example 10, and will not be described again here.

[0154] In summary, the toothed thin-walled structure provided by this invention can effectively reduce the "shear hysteresis effect" caused by bending during the expansion and contraction of the "pod structure," prevent local thin-wall instability and outward warping (wrinkling or unevenness) of the pod slices caused by uncoordinated longitudinal deformation of the pod stalk, and at the same time, the toothed texture can act as a stiffening rib for the elastic sheet to increase the bending stiffness of the structure.

[0155] The toothed surface thin-walled structure deployment and retraction mechanism proposed in this invention can effectively solve the problems of use and adaptation of the device in different fields through various connection methods and extension / retraction methods, thus expanding the application range of the device. It can serve as a supporting frame for flexible devices such as flexible solar cells and thin-film antennas, and has the advantages of being lightweight, having a high storage ratio, a large unfolded area, easy to rewind, bearing a large load, and being not easily damaged.

[0156] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A mechanism for deploying and retracting a thin-walled structure having a textured surface, characterized by, It includes a drum assembly, a pressure roller assembly, and a resilient adjustment mechanism integrated together via a frame, the resilient adjustment mechanism being used to maintain the resilient pressing tendency of the drum assembly and the pressure roller assembly; The drum assembly includes a drum shaft and a drum rotatably connected to the drum shaft; the pressure wheel assembly includes a pressure wheel shaft and a pressure wheel rotatably connected to the pressure wheel shaft; the surfaces of the drum and the pressure wheel are respectively provided with transmission teeth for meshing with the toothed surface toothed structure. The toothed surface thin-walled structure is a single-layer toothed surface thin-walled structure that can be flattened and bent, or a multi-layer toothed surface thin-walled structure that can be stacked and bent. The surface of the toothed surface thin-walled structure has a toothed structure for transmitting interlayer shear force or meshing transmission. The elastic adjustment mechanism is connected between the reel and the frame, or between the pressure roller and the frame, or between the reel and the pressure roller; The drum and pressure roller apply a clamping force to the toothed thin-walled structure through the elastic adjustment mechanism to ensure engagement during the unfolding and rewinding process.

2. The mechanism according to claim 1, wherein The single-layer toothed thin-walled structure is a C-shaped cross-section rod; The multi-layered toothed thin-walled structure is one of the following: toothed pod rod, toothed pod core plate, double C-shaped cross-section rod, herringbone cross-section rod, and Z-shaped cross-section rod.

3. The unfolding and retracting mechanism with a toothed surface thin-walled structure according to claim 2, characterized in that, The serrated bean pod core board includes a first elastic thin plate, a second elastic thin plate, and a hollow elastic sandwich layer disposed between the first elastic thin plate and the second elastic thin plate. Under the action of compression force, the first elastic thin plate and the second elastic thin plate can be stacked with the hollow elastic sandwich layer to form a bendable layered structure.

4. The unfolding and retracting mechanism with a toothed surface thin-walled structure according to claim 3, characterized in that, The hollow elastic sandwich layer is made of semi-split toothed bean pod rod, and the outer surface of the first elastic thin plate and the second elastic thin plate has a toothed section on at least one side, and the rest is a smooth section.

5. The unfolding and retracting mechanism with a toothed surface thin-walled structure according to claim 3, characterized in that, The hollow elastic sandwich layer includes a plurality of toothed pods arranged in sequence, and at least one side of the first elastic plate and the second elastic plate has toothed pods exposed to form a toothed section. The outer surfaces of the first and second elastic plates are smooth.

6. The unfolding and retracting mechanism of the toothed surface thin-walled structure according to claim 1, characterized in that, The elastic adjustment mechanism is a cantilever elastic support assembly, and both ends of the drum shaft or the pressure wheel shaft are connected to the frame through the cantilever elastic support assembly; The cantilevered elastic support assembly includes a cantilever and an elastic hinge assembly. One end of the cantilever is connected to the drum shaft or the pressure wheel shaft, and the other end is hinged to the frame through the elastic hinge assembly.

7. The unfolding and retracting mechanism of the toothed surface thin-walled structure according to claim 1, characterized in that, The elastic adjustment mechanism is a scissor-type elastic support assembly, and the two ends of the drum shaft are respectively connected to the corresponding ends of the pressure wheel shaft through the elastic support assembly; The scissor-type elastic support assembly includes a pair of scissor blades and an elastic hinge assembly that hinges one end of the pair of scissor blades. The ends of the scissor blades away from the elastic hinge assembly are respectively connected to the end of the drum shaft and the end of the pressure wheel shaft.

8. The unfolding and retracting mechanism of the toothed surface thin-walled structure according to claim 6 or 7, characterized in that, The elastic hinge assembly includes a hinge shaft, a locking element, and a torsion spring. The hinge shaft is equipped with a torsion spring, which is connected between the cantilever and the frame. The torsion spring stores elastic potential energy for driving the cantilever to continuously roll and press the toothed thin-walled structure with the drum and the pressure wheel.

9. The unfolding and retracting mechanism of the toothed surface thin-walled structure according to claim 1, characterized in that, The elastic adjustment mechanism is a C-type elastic connecting frame, and the two ends of the drum shaft are respectively connected to the corresponding ends of the pressure wheel shaft through the C-type elastic connecting frame.

10. The unfolding and retracting mechanism of the toothed surface thin-walled structure according to claim 1, characterized in that, The clamping roller is a single-section clamping roller or a multi-section clamping roller. The clamping roller shaft of the multi-section clamping roller is connected to the frame by one or more open cantilever elastic support assemblies or cantilever elastic support assemblies for increasing rolling stiffness. The open cantilever elastic support assembly includes an open cantilever, one end of which is connected to the pressure wheel axle, and the other end is connected to the frame via a hinge shaft. A torsion spring is installed on the hinge shaft, and the torsion spring is connected between the open cantilever and the frame.

11. The unfolding and retracting mechanism of the toothed surface thin-walled structure according to claim 1, characterized in that, The toothed thin-walled structure is provided with a widened portion on at least one side of the connection end with the drum, and the frame is provided with a blocking block for blocking the widened portion.

12. The unfolding and retracting mechanism of the toothed surface thin-walled structure according to claim 1, characterized in that, It also includes a drive mechanism for driving the pressure roller or drum to rotate; The frame is equipped with at least one stop switch, and the drive mechanism is electrically connected to the stop switch so as to stop when the toothed surface thin-walled structure expands and contracts to its limit position.

13. The unfolding and retracting mechanism of the toothed surface thin-walled structure according to claim 1, characterized in that, The deployment and retraction mechanism can be a single-unit or dual-unit type; When the unfolding and retracting mechanism is a single unit, the toothed thin-walled structure unfolds at the outlet end of the unfolding and retracting mechanism. When the unfolding and taking-up mechanism is a dual-machine type, the toothed thin-walled structure is unfolded between the two unfolding and taking-up mechanisms or wound and stored on the rolls within both.

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