70 results about "Long arm" patented technology

This invention relates to the field of medical devices, and more particularly to a valve clip with a locking mechanism, comprising a first clamping arm, a second clamping arm, a connecting member, a push-pull device, and a locking device. The locking device partially cooperates with the connecting member, and includes a locking head and a self-locking rod. The connecting member is hinged to the first clamping arm and the second clamping arm respectively. The clamping arm includes a long arm and a short arm. One end of the long arm is hinged to the push-pull device, and one end of the short arm is provided with a locking part. When the push-pull device is operated to increase the angle between the long arms of the first and second clamping arms, the locking part on the first clamping arm and the locking part on the second clamping arm are partially misaligned. When the push-pull device is operated to decrease the angle between the long arms of the first and second clamping arms, the locking device is moved to allow the locking head to engage with the locking part and lock.

The utility model provides a kind of movement device of cylinder sewing machine feed dog, belong to sewing machine technical field.It solves the problem that existing feed dog movement device is not applicable to cylinder sewing machine.This sewing machine includes the cabinet with long arm, the first end of swing arm is fixed with feed dog, the middle part of swing arm is hinged with long arm, the first end of lifting tooth bar is hinged with long arm, the first end of lifting tooth bar is located directly below the first end of swing arm, lower shaft can drive swing arm swing back and forth around its hinged point by feeding assembly, lower shaft can drive lifting tooth bar swing up and down around its hinged point by lifting tooth assembly, the first end of lifting tooth bar swing upwards can make the first end of swing arm move upwards, swing arm can make the first end of swing arm move downwards under the action of its elasticity.This movement device of cylinder sewing machine feed dog has the advantages of reasonable use of space, smooth movement of cylinder sewing machine feed dog.

The utility model discloses an insertion type long arm draw hook and a multi-hook buccal tube, the insertion type long arm draw hook comprises a tenon tongue part, a draw arm and at least one draw hook, the tenon tongue part is used for being installed on the buccal tube, the draw arm is connected to the side, away from the buccal tube, of the tenon tongue part, and a certain included angle is formed between the draw arm and the tenon tongue part; the traction hook is arranged at one end of the traction arm away from the tenon tongue part. A certain included angle is formed between the tenon tongue part and the traction arm, so that the traction arm can avoid gingiva, compression on the gingiva is effectively avoided, and the comfort level of a patient during wearing is further improved while the functionality of the traction arm in clinical application is ensured.

The utility model provides a balance forklift vertical holding clamp which is characterized in that an accessory connecting mechanism is arranged on one side of a base plate; the two mechanical arms are hinged to the side, away from the forklift, of the base plate correspondingly and arranged in the horizontal direction. The two mechanical arms are different in length and are respectively a long arm and a short arm; the long arm and the short arm are arc-shaped respectively, and the concave surfaces are positioned on the sides, close to each other, of the long arm and the short arm respectively; the driving mechanism is installed on the base plate, connected with the mechanical arm and used for driving the mechanical arm to rotate relatively. The butt joint mechanism is hinged to the end, away from the base plate, of the mechanical arm. By means of the long arm and the short arm which are different in length and are in an arc shape, when coiled floor heating pipes with different diameters are grabbed, more flexible grabbing action can be achieved through the rotating speed difference; the long arm expands the overall grabbing radius and can adapt to various package specifications, the short arm is relatively flexible, the clamping capacity is improved through three-point contact, and therefore the carrying applicability of the packaged floor heating pipe is greatly improved.

The utility model relates to the field of data centers, and discloses an independent insertion assisting device and a data center, which are used for realizing manual insertion interconnection of a server and a cabinet on the basis of not occupying the space of the server. The independent insertion assisting device comprises a fixed plate, a movable plate, an insertion assisting handle and a fixing structure. The fixing structure is arranged on the fixed plate and used for fixing the fixed plate; the fixed plate and the movable plate are arranged in the first direction, and the movable plate can be driven by the insertion assisting handle to be away from or close to the fixed plate in the first direction. The insertion assisting handle comprises a long arm and a short arm, the first end of the short arm is slidably connected with the movable plate in the second direction, and the second end of the short arm is rotationally connected with the fixed plate through a rotating shaft. The second direction is perpendicular to the first direction; the first end of the long arm is connected with the second end of the short arm, and the second end of the long arm penetrates through the fixed plate and extends out of the side, away from the movable plate, of the fixed plate. The distance between the second end of the long arm and the rotating shaft is larger than that between the first end of the long arm and the rotating shaft.

This invention discloses a welding process equipment with an internal cavity long-arm fixed support mechanism, including a support base, a bottom positioning mechanism on the support base, and an internal cavity fixed support mechanism, a bottom clamping mechanism, and a side clamping mechanism. The bottom positioning mechanism and the internal cavity fixed support mechanism cooperate to form a welding part placement area. This invention enables rapid, accurate, and stable clamping of welding parts, as well as balanced support for the welding parts, preventing deformation and stress during the welding process, improving welding quality and efficiency, reducing labor costs and errors, and is applicable to welding parts of more shapes and sizes.

A long arm type compact wheel bucket excavator relates to mechanical equipment for open pit mining, comprising a supporting mechanism, a bucket wheel driving mechanism, a discharging arm rotating mechanism, a crawler walking mechanism and a tensioning mechanism, the discharging arm rotating mechanism comprising a main machine walking mechanism, a supporting base assembly, a rotating platform assembly and an adjusting plate assembly; the supporting base assembly comprising a central pipe vertically fixed on the main machine walking mechanism and a mounting seat fixed on the central pipe; the rotating platform assembly comprising a rotating platform rotatably supported on an L-shaped beam; the adjusting plate assembly comprising an adjusting plate body, a lower connecting shaft slide way symmetrically arranged on both sides of the adjusting plate body and an upper connecting shaft slide groove symmetrically arranged on the other two sides of the adjusting plate body, the guide directions of the lower connecting shaft slide way and the upper connecting shaft slide groove being perpendicular to each other. The wheel bucket excavator does not need to additionally set a reclaimer and will not generate triangular coal, and has the advantages of good stress characteristics, good safety and the like.

The utility model provides a novel draw hook which comprises a draw hook body, the draw hook body comprises a long-arm draw hook, a short-arm draw hook and a shoulder connecting body, and the long-arm draw hook and the short-arm draw hook are connected in an L shape through the shoulder connecting body; the shoulder connecting body is provided with at least one group of kirschner wire positioning holes, and the extending direction of the kirschner wire positioning holes is parallel to the length direction of the short-arm drag hook. Or / and the extending direction of the kirschner wire positioning holes is parallel to the length direction of the short-arm drag hook, and the extending direction of all the kirschner wire positioning holes is located on the outer side of the body; through the double-end design of the retractor body, the long-arm retractor or the short-arm retractor can be selected according to the quantity of soft tissues; the Kirschner wire positioning hole is formed in the shoulder connecting body of the drag hook body, and during an orthopedic operation, after the drag hook is dragged to a preset position, a Kirschner wire is driven into the Kirschner wire positioning hole to fix the drag hook body on a bone substance, so that an operation assistant can be liberated, meanwhile, the number of operation instruments is reduced, and the operation is conveniently carried out.

To realize a module type replaceable transport unit, height adjustment of the transport unit, removal of the transport unit, and automatic reduction of a chassis into the smallest folding size without disassembly.SOLUTION: A folding device for transporting goods includes: a first platform; a second platform; and a lift having a plurality of folding crossing portions rotatably coupled to the first platform and the second platform. Each of the plurality of folding crossing portions includes a first long arm, a second long arm and a short arm. The first long arm is fixedly connected to the second long arm.SELECTED DRAWING: Figure 6

The utility model discloses an automatic propulsion auxiliary device based on lengthened cutter machining, which relates to the field of lengthened cutter machining and comprises a base, a movable block is fixedly mounted at the top of the base, a rotating shaft is fixedly mounted above the movable block, a long arm is rotatably mounted on the outer side of the rotating shaft, and a polishing wheel is rotatably mounted on one side of the long arm. The grinding wheel is electrically connected with an external power source, a folding assembly is movably installed between the long arm and the base and electrically connected with the external power source, a cushion block is fixedly installed above the base, a positioning seat is fixedly installed above the cushion block, a tool bit workpiece is arranged in the positioning seat and corresponds to the grinding wheel, and the grinding wheel is electrically connected with the tool bit workpiece. According to the tool bit machining device, the machining process can be monitored in real time, machining safety is improved, manual observation is not needed due to the two-way propelling mode, and working efficiency is improved.

The utility model discloses a kind of suspension long component tail end reinforcing structures, including suspension long arm, the one end of the suspension long arm is throughly provided with mounting seat, to install connection to entire suspension long component, the end surface of the suspension long arm is tightly provided with fixed block, to provide the stable strength of entire suspension long component in use, the one end of the suspension long arm is provided with suspension end, when being used to entire suspension long component, it can be injected with suspension end and be inserted in the inside of mould to carry out injection molding processing, improve the convenience in processing process. The utility model increases fixed block in the one end of suspension long component, under the holding of fixed block, so that suspension long component can keep stable for a long time in use, and improve the service life of suspension long component.

The utility model discloses a heavy-duty dustproof hinge, which relates to the technical field of hinges, and comprises a bottom plate and a support arm for installing a window, the middle section of the bottom of the support arm is hinged with a long arm through a pin shaft, the top of the bottom plate is clamped with a connecting gasket, the top of the connecting gasket is provided with a short arm and a middle arm, and the short arm is connected with the middle arm. The short arm and the middle arm are hinged to the bottom plate through pin shafts, and the short arm is hinged to the supporting arm through a pin shaft; according to the sliding support hinge, the square rivet is riveted at the bottom of the supporting arm in a pressing mode, when the sliding support hinge is opened to the maximum degree, the angle limiting inclined face on the short arm and the angle limiting inclined face on the middle arm make contact with each other and are clamped with each other, the square rivet makes contact with the long arm and blocks the long arm, and a secondary wind resistance structure is achieved. And continuous acting force acts on the square rivet, the angle limiting inclined plane on the short arm and the angle limiting inclined plane on the middle arm, so that the wind resistance is improved, and the deformation and damage of the sliding support hinge are avoided.

The utility model relates to an adjustable rotating structure of a display screen on a marine display and control console, which comprises a display and control console frame body and the display screen, one end of the display screen is connected with the outside of the upper part of the display and control console frame body through a hinge, and a rocker arm structure is arranged between the back surface of the display screen and the inside of the upper part of the display and control console frame body; the rocker arm structure comprises a fixed arm, a movable short arm, a movable long arm, a supporting seat and an adapter plate, the fixed arm is connected into the upper portion of the display and control table frame, one end of the movable short arm is rotationally connected with the fixed arm, the other end of the movable short arm is rotationally connected with one end of the movable long arm, the other end of the movable long arm is rotationally connected with the supporting seat, and the supporting seat is connected to the adapter plate. The adapter plate is fixedly arranged in the middle of the back of the display screen. According to the utility model, through the combination of the hinge and the rocker arm structure, turning and supporting moment at any angle of 0-90 degrees can be provided for the display screen, so that the display screen has the function of hovering at any angle, and an operator can adjust the use visual angle at multiple angles and carry out maintenance work.

The utility model discloses a novel long-arm positive-axis spring for adjusting canine axis inclination, and relates to the technical field of orthodontics, the novel long-arm positive-axis spring comprises a connecting arm, a force application arm, a sliding arm and an elastic force storage part, the two ends of the connecting arm are connected with the force application arm and the sliding arm through the elastic force storage part respectively, and the elastic force storage part is connected with the connecting arm. And a hook is arranged at one end, far away from the elastic force storage part, of the sliding arm. According to the orthodontic appliance, canine teeth can be controlled to incline in the required direction, the force application size and direction of the orthodontic appliance are controllable, the teeth can be efficiently aligned while comfort is considered, the orthodontic materials are easy to obtain, manufacturing is easy and convenient, and the orthodontic appliance can be widely applied and popularized.

The invention discloses a micro-vibration conversion and transmission structure and a micro-vibration generation device.The micro-vibration conversion and transmission structure comprises a cross beam, a bearing, a blocking piece, a support and a mass block, the bearing comprises a knife edge and a knife bearing, the cross beam and the knife edge are fixedly installed, and vibration transmission is achieved through left-right swinging of the knife edge on the knife bearing; the cross beam is an unequal-proportion lever and comprises a long arm and a short arm, and equal-proportion reduction conversion of vibration signals can be achieved through the arm length proportion of the long arm and the short arm; the separation blade is used for vertically supporting and constraining the transverse movement of the cross beam; a cutter bearing of the support is fixedly mounted on the support, and a mass block is fixedly mounted on the cross beam and used for adjusting the height of the gravity center of the micro-vibration conversion and transmission structure; a threaded hole in the end of the long arm is connected with a vibration excitation source, and a threaded hole in the end of the short arm is provided with a micro-vibration sensor. The vibration magnitude of an existing excitation system can be reduced according to a certain proportion and then converted into a micro-vibration signal, and the calibration requirement of a micro-vibration sensor under the low-frequency micro-vibration magnitude is met.

The application relates to an automatic guiding deviation rectifying device, and relates to the field of modern automobile industrial production and manufacturing. The device comprises a deviation rectifying mechanism and a return mechanism. The deviation rectifying mechanism comprises a rotating arm, the rotating arm comprises a long arm and a short arm used for driving the long arm to be lifted after the long arm is driven to descend when the plate contacts the front end of the long arm, the front ends of the long arm and the short arm are upwardly arranged and are mutually angled, a rotating pin is arranged in the middle of the rotating arm so as to divide the rotating arm into the long arm and the short arm, and the return mechanism comprises an elastic component used for descending the short arm to return when the plate leaves the long arm. The rotating pin and the deviation rectifying mechanism are adopted to rectify the plate through the tilting and rotating mode. The deviation rectifying device has the advantages of strong deviation rectifying capacity, high efficiency, large deviation rectifying range, larger deviation rectifying moving distance compared with the existing deviation rectifying mechanism, small friction force generated during deviation rectification, and difficulty in being stuck during the deviation rectification of the plate.

The application discloses a variable wheel suitable for complex driving road surfaces, the spoke of the variable wheel comprises three spoke plates of adult letter-shaped structure; the wheel leg is in circular arc structure and corresponds to the spoke plate one by one; the duct is provided with a web; the rotor is coaxially installed in the duct; the Z-shaped component comprises a long arm, a fixed shaft and a short arm; one end of the fixed shaft is rotationally connected with the long arm, and the other end is rotationally connected with the short arm; the roller at the outer end of the long arm is rollingly matched in the groove, and the rollers at both ends of the roller are slidingly matched with the guide rail groove; the traction rod is rotationally connected with the short arm; the driving disc is connected with the traction rod; the first driving shaft is fixedly connected with the rotor in concentricity; the second driving shaft is fixedly connected with the driving disc in concentricity; and the third driving shaft is fixedly connected with the spoke in concentricity. The variable wheel has simple structure, good stability and can realize wheel type, leg type and duct rotor type.

The utility model discloses a stable folding boom easy to operate, which relates to the technical field of mining equipment and comprises a connecting unit, a first adjusting unit and a second adjusting unit, the first adjusting unit and the second adjusting unit are arranged above the connecting unit, and the second adjusting unit is positioned on the side of the first adjusting unit. The first adjusting unit comprises a U-shaped base installed on the top of the connecting unit, a first-stage arm movably installed on the top of the U-shaped base, and a first adjusting piece arranged between the U-shaped base and the first-stage arm. According to the stable folding arm support easy to operate, due to the arrangement of the first adjusting unit and the second adjusting unit, the long arm support can keep high stability in the working state, and the shaking phenomenon caused by a long arm is reduced.

This invention relates to the field of bridge pier positioning device technology, specifically to a bridge pier column installation and positioning structure and method. The structure includes a first rectangular frame surrounding the pile foundation, comprising two L-shaped arms. Each L-shaped arm has an external mounting base on one arm, and each mounting base has a self-adjusting structure. The self-adjusting structure includes a first base, a linear movement structure at the lower end of the first base, and a V-shaped arm at the upper end of the first base. The V-shaped arm has a short arm and a long arm, which meet at the upper end of the first base and are hinged. A first U-shaped frame is provided at one end of the short arm, and a first roller is provided on the first U-shaped frame. Two jack support structures are symmetrically arranged on both sides of the self-adjusting structure. This invention, with its self-adjusting structure and jack support structures, achieves automatic adjustment of the pier column's position, preventing manual placement under potentially tilting pier columns.

The utility model discloses an ergonomic workbench for equipment maintenance, which comprises a workbench body and an elbow supporting mechanism, and the elbow supporting mechanism comprises a butt-mounting plate, a chute plate, a T-shaped middle plate, a supporting strip, an L-shaped guide frame, a rubber supporting cushion, an L-shaped elbow supporting plate and a supporting cushion block, opposite installation plates are symmetrically locked below a platen, away from a lifting support of the workbench body, of the workbench body through bolts, an elbow supporting mechanism is arranged at the position, meeting human engineering, of the workbench body, and the elbow supporting mechanism is innovatively provided with an L-shaped elbow supporting plate capable of sliding transversely for the problem that the elbows of a worker with the long arms are suspended. The L-shaped elbow supporting plate is matched with the sliding groove plate through the T-shaped bolt and can transversely move along the edge of the workbench and be locked at any position, the elbow is naturally placed on the supporting cushion block, a stable supporting face is formed, the elbow supporting mechanism avoids the situation that the elbow is suspended due to a fixing structure of a traditional workbench, and continuous tension of muscles of the shoulder and the elbow is reduced.

A kind of hanging device, system and method, the device includes device body, long arm, short arm, support arm, first elastic member and second elastic member;The first end of long arm is rotatably connected with the first side of the end of device body by first elastic member;The first end of short arm is rotatably connected with the second side of the end of device body by second elastic member;The first end of support arm is rotatably connected with the second end of one of long arm and short arm;The distance between the first end and the second end of long arm is greater than the distance between the first end and the second end of short arm, and the rotation plane of long arm and short arm is parallel;In the case where the second end of support arm is in abutment with short arm or long arm, long arm and short arm form an opening with an intermediate region;In the case where the second end of support arm is out of abutment with short arm, long arm and short arm respectively move along the rotation plane and approach the end of device body under the action of first elastic member and second elastic member to realize hanging / clamping, thereby improving the hanging success rate.

The utility model relates to communication pipeline construction technical field, concretely is a kind of pipeline support auxiliary equipment for communication pipeline construction, including fixed mechanism between the both ends of guide rail, the fixed mechanism includes two L type sliding blocks, and the long arm bottom end of two L type sliding blocks is all slidingly connected in the inside of guide rail, two-way screw rod is rotatably connected between the both ends of the inside of guide rail, and the long arm of two L type sliding blocks is all provided with threaded hole. In the utility model, by rotating two-way screw rod, two L type sliding blocks are moved towards and clamped to be installed plum blossom pipe, then two-way screw rod is rotated, and adjacent two clamping blocks are moved away from each other, so as to adjust the distance between frame body and guide rail, then according to the shape of plum blossom pipe that has been installed, two rotating frames are rotated, and moving wheel is in contact with plum blossom pipe that has been installed, so that guide rail, L type sliding block and frame body support plum blossom pipe to be installed, so as to support plum blossom pipe to be installed, so as to facilitate user to carry out socket operation.

The invention, which relates to the technical field of the coast environment, discloses a coast environment monitoring and early warning device comprising a support and a monitoring and adjusting device. The monitoring and adjusting device is arranged, that is, when a rotating disc arranged in a first adjusting assembly rotates, a short arm can be driven through a connecting shaft arranged at the outer end, a long arm connected with the short arm can be matched with a fixed shaft in butt joint with one side, smooth unfolding is achieved, and therefore the monitoring and adjusting effect is achieved. The second adjusting assembly indirectly drives the monitoring camera connected with the upper end of the second adjusting assembly to move outwards, so that the monitoring position is flexibly expanded and adjusted, the monitoring range is widened, and meanwhile, a rotating frame in the second adjusting assembly is matched to rotate, a connecting arm can drag a sliding block, and the sliding block is guided by a guide ring to slide up and down to adjust the monitoring angle and position of the monitoring camera. Therefore, the monitoring camera is more flexible and diversified in monitoring and use, and meets the requirement for efficient monitoring and use of the bay environment.

The utility model discloses a portable invisible clothes hanger which comprises a groove body frame, symmetrically distributed sliding grooves are connected in the groove body frame, folding arms are rotationally connected to the two ends in the groove body frame respectively, long arms are rotationally connected to the opposite sides of the two folding arms respectively, and one ends of the long arms are in sliding connection with the two sliding grooves through sliding rods. The other ends of the long arms are rotationally connected with positioning sleeves, a fixed insertion pipe is connected between the two sets of positioning sleeves in a sleeved mode, and extension pipes are connected to the two ends of the fixed insertion pipe in an inserted mode respectively. The beneficial effects are that service life is prolonged and space is saved.

The application relates to the technical field of cabin cover tooling, and discloses a portable full-working-condition cabin cover sealing rubber installation tooling which comprises a supporting rod, the supporting rod is in the shape of a Chinese character '7', an antiskid plate is fixedly arranged at the top of the supporting rod, a limiting rod is arranged on one side of the middle part of the supporting rod, handles are arranged on the outer walls of the middle part of the supporting rod and located on the two sides of the limiting rod, a plurality of through adjusting holes are formed in the lower half of the supporting rod, a rotating frame is rotatably arranged outside one of the adjusting holes, a long arm is arranged on the outer wall of one end of the rotating frame, a short arm is arranged on the outer wall of the other end of the rotating frame, and a pressing block is arranged on one end of the short arm, the application can be applied to the installation of cabin cover sealing rubbers in the lifting-off type, side-moving type and folding type, has a wide application range, basically meets the requirements of cabin cover rubber strip installation under various working conditions, reduces the condition limitation of cabin cover rubber strip replacement, reduces the total cost of rubber strip replacement, can greatly reduce the labor intensity of workers and improve the work efficiency.

The utility model relates to the technical field of heating appliances, in particular to a panel support structure of an induction cooker and an electric ceramic cooker, which comprises a frame for supporting a panel, and the frame comprises two long arms and two short arms; wherein the two long arms rotate by 90 degrees around the central axis of the frame and are horizontally arranged, and the two ends of the two long arms are staggered; the two short arms rotate around the central axis of the frame by 90 degrees. According to the utility model, the two long arms and the two short arms are connected to form a complete frame, so that the whole plate does not need to be subjected to hole cutting processing, and the supporting stability of the panel can be ensured while materials are saved; and secondly, a positioning structure is also arranged between the long arm and the short arm, so that the accuracy of the connecting position of the long arm and the short arm in the assembling process can be ensured, a flat supporting surface can be formed on the panel, and the stress of the panel is kept uniform.

The application relates to a display folding lifting base and a use method, which comprises a base, support arms installed on the base, a display adapter plate installed on the upper portion of the support arms through a lifting assembly, two long-arm front supporting legs symmetrically installed on the front side of the base, a short-arm rear supporting leg installed on the middle portion of the rear side of the base, the long-arm front supporting leg and the short-arm rear supporting leg being hinged to the base, a limiting piece for fixing the short-arm rear supporting leg in an unfolded supporting state and a folded storage state being arranged on the base, a rotating shaft being vertically installed in the base, a knob being fixedly installed on the lower end of the rotating shaft, two limiting convex portions being symmetrically arranged on the outer periphery of the middle portion of the rotating shaft, and a clamping arm for cooperating with the limiting convex portions being arranged on the inner end of the long-arm front supporting leg; the display folding lifting base is simple in structure, reasonable in design, foldable, does not need to be disassembled and assembled with the base, convenient to store and pack, small in occupied area, low in packaging cost, can stably support the display, and has good social and economic benefits.

A zero-wall trifold sofa bed includes a sofa base, where the sofa base is provided with two symmetrical folding assemblies; the folding assemblies each include a first long arm and a second long arm that are pivoted to a front side of an inner wall of an armrest box of the sofa base; the first long arm and the second long arm are jointly pivoted to a first assembly element for assembling a first sofa base; a middle part of the first long arm is provided with a first short arm; a middle part of the second long arm is provided with a second short arm and a third short arm; the first short arm and the second short arm are jointly pivoted to a second assembly element for assembling a second sofa base; the third short arm is pivoted to one end of a connecting rod.

The utility model aims to provide a folding ladder stand which is used for being installed on a water tank and comprises a ladder main body and a folding assembly, the top end of the ladder main body is rotatably connected with the top of the water tank, the folding assembly comprises two long arms and two short arms, one ends of the two long arms are rotatably connected with the bottom end of the ladder main body, and the two long arms are located on the two sides of the ladder main body respectively. One ends of the two short arms are rotationally connected with the bottom of the water tank, the other ends of the two short arms are rotationally connected with the other ends of the two long arms respectively, and the length of the long arms is larger than that of the short arms; the minimum distance between one end of the short arm connected to the water tank and one end of the long arm connected to the ladder main body is equal to the length difference between the long arm and the short arm. Therefore, under the matching action of the ladder main body, the long arm and the short arm, the folding ladder stand can be folded so as to be convenient to transport, and space occupation is avoided when the folding ladder stand is not used.

The application relates to the technical field of arc-shaped pipeline installation, and particularly discloses a device for measuring the length of an arc-shaped pipeline, which is used for measuring the length of an arc-shaped pipeline in a concentric arc-shaped structure; the device is characterized in that the device is located between two structural columns and connected with one of the structural columns; the device comprises a support arm horizontally installed on the structural column, and a plurality of tape members installed on the support arm and sliding along the length direction of the support arm; the support arm is in an L shape and comprises a short arm vertically arranged and connected with the structural column, and a long arm perpendicularly connected with the other end of the short arm and slidingly matched with the tape members. The device can effectively realize the length measurement of the arc-shaped pipeline, has high accuracy, reduces the generation of waste materials, and reduces the construction cost.