CN210528240U - Lifting appliance for prefabricated part - Google Patents

Abstract

The utility model discloses a lifting appliance of a prefabricated part, which comprises a beam, a positioning component, a lifting rope and a sling, wherein the upper surface of the beam is provided with a plurality of lifting lugs, and one end of the lifting rope is fixed with the lifting lugs; the positioning assembly comprises a sliding block frame, a fixed pulley and a fixed pin, the fixed pin fixes the top end of the sliding block frame on the fixed hole, the fixed pulley is fixed on the bottom surface of the sliding block frame, the middle part of a sling is arranged on the surface of the fixed pulley, and lifting hooks are arranged at two ends of the sling respectively. According to the lifting appliance, the cross beam is uniformly provided with the plurality of fixing holes, the positioning assemblies can be fixed on the corresponding fixing holes according to needs, and the prefabricated part is lifted through the lifting rope, so that the application range is wide, and the universality is high; through setting up stop gear, guarantee to carry and draw the slip of rope on locating component and be in certain extent, improved the security and the maneuverability of hoist.

Description

Lifting appliance for prefabricated part

Technical Field

The utility model belongs to the technical field of the assembly type structure production, specifically speaking, the utility model relates to a prefabricated component's hoist.

Background

In the fabricated building, most of components such as wallboards, floor slabs, beams and the like can be produced in a factory, hanging nails can be pre-buried during production, and after production and maintenance are completed, the prefabricated components are lifted by the hanging nails and then conveyed to a storage yard for storage or conveyed to a construction site for installation by a lifting appliance. In the prior art, because the prefabricated wall panel is very thick and heavy and has a large area, after the maintenance of the prefabricated wall panel produced on a flow production line is completed, a worker must climb the escalator to hook the hook of the lifting appliance with the hanging nail pre-embedded in the prefabricated part before lifting, a crane or a traveling crane is adopted for moving, and the worker needs to hold the prefabricated wall panel to reduce the swinging of the prefabricated wall panel in the moving process. After the lifting is completed, the worker is required to climb the escalator again to take off the hook. Therefore, the hoisting process needs manual hooking, holding and unhooking, so that time and labor are wasted, the operation efficiency is low, and the production efficiency is seriously influenced on a prefabricated part production line with high yield; but also brings about potential safety hazards.

Prefabricated wallboard specification differs, still can design has door opening or window opening, and to the wallboard of different specification and dimension, the hoist of different specifications need be changed to the workman like this, and the workman need use tools such as cat ladder, hammer to accomplish the handling operation, and the commonality of hoist is lower, and compatible scheduling problem such as not strong, and hoist and mount efficiency is lower. In view of the above, it is necessary to develop a lifting device suitable for prefabricated parts with different dimensions.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is: the utility model provides a hoist of prefabricated component to solve the hoist commonality that exists among the prior art and compatible not strong, can't be applied to the technical problem of lifting by crane of the prefabricated component of different specification and dimension.

In order to realize the purpose, the utility model discloses the technical scheme who takes does:

a lifting appliance for prefabricated parts comprises a cross beam, a positioning assembly, a lifting rope and a sling, wherein a plurality of lifting lugs are arranged on the upper surface of the cross beam, and one end of the lifting rope is fixed with the lifting lugs; the positioning assembly comprises a sliding block frame, a fixed pulley and a fixed pin, the fixed pin fixes the top end of the sliding block frame on the fixed hole, the fixed pulley is fixed on the bottom surface of the sliding block frame, the middle part of a sling is arranged on the surface of the fixed pulley, and lifting hooks are arranged at two ends of the sling respectively.

Preferably, the lifting rope further comprises a power mechanism, the other end of the lifting rope is fixed to the power mechanism, and the power mechanism drives the cross beam to move in the vertical direction through the lifting rope.

Preferably, the limiting mechanism comprises a limiting sliding block and a limiting part, the limiting sliding block is arranged on the cross beam, a through hole is formed in the bottom side of the limiting sliding block, the sling passes through the through hole, and the limiting part is a sheet-shaped body or a strip-shaped body which is arranged on the sling and has a size larger than that of the through hole.

Preferably, the limiting mechanism is fixed on a cross beam between the two positioning assemblies.

Preferably, the limiting slide block is fixed on the fixing hole through a fixing pin.

Preferably, the cross beam is provided with a slide rail, and the slide block frame is provided with a slide block matched with the slide rail.

Preferably, the slider frame is a hollow box structure, the top of the slider frame extends upwards to form a fixed plate, and the fixed plate is provided with a hole for the fixed pin to pass through.

Preferably, a pi-shaped support frame is fixed on the bottom surface of the slider frame, the fixed pulley is located inside the support frame, and two ends of a shaft of the fixed pulley are fixed on two side plates of the support frame.

Preferably, the lifting hook comprises a fixed seat, a power unit, an adjusting piece and a hoop unit; the power unit is fixedly connected with the fixing seat, the fixed end of the hoop unit is clamped on the fixing seat, the power unit drives the adjusting piece to move vertically, and the adjusting piece drives the free end of the hoop unit to open or close.

Preferably, the fixing seat is further provided with a clamping block, one end of the clamping block is fixed to the fixing seat, and the other end of the clamping block is arranged in the fixing seat and clamped to the upper surface of the fixing end of the hoop unit.

Preferably, the power unit comprises a push rod, the circumference of the middle section of the adjusting piece is smaller than the circumferences of the two ends of the adjusting piece, and the top end of the adjusting piece is connected with the push rod; the hoop unit is enclosed at the outer edge of the adjusting piece and comprises at least two hoop blocks and annular springs enclosed at the peripheries of the hoop blocks, the width of the fixed end of the hoop unit is smaller than that of the free end, the annular springs are arranged at the peripheries of the fixed end, and the bottom end of the free end is provided with a pawl; the push rod of the power unit drives the adjusting piece to vertically move in the hoop unit, and free ends of adjacent hoop blocks are driven to be separated or folded, so that the pawl performs opening or folding actions.

The technical scheme of the utility model the beneficial technological effect who gains is:

1. according to the lifting appliance for the prefabricated part, the cross beam is uniformly provided with the plurality of fixing holes, the positioning assemblies can be fixed on the corresponding fixing holes according to the specification and the size of the prefabricated part to be lifted, the prefabricated part is lifted through the sling, the lifting appliance can be suitable for prefabricated parts with various specifications and sizes, and is wide in application range and high in universality;

2. according to the lifting appliance of the prefabricated part, the limiting mechanism is arranged, so that the sliding of the sling on the positioning assemblies is within a certain range, the unbalanced length of the sling on the two positioning assemblies caused by the uneven gravity center of the prefabricated part in the lifting process is avoided, and the safety and the operability of the lifting appliance are improved;

3. the lifting hook of the lifting appliance of the prefabricated part in the scheme can realize automatic hooking and unhooking of the pre-buried lifting nail in the prefabricated part, is high in automation degree and convenient to operate, improves the lifting efficiency of the prefabricated part, and reduces the potential safety hazard when the prefabricated part is lifted.

Drawings

The accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation.

Fig. 1 is a schematic structural view of a spreader in embodiment 1 (hidden power mechanism);

FIG. 2 is an enlarged view of a portion of the spreader of FIG. 1;

fig. 3 is a schematic perspective view of the positioning assembly of the present invention;

fig. 4 is a side view of the positioning assembly of the present invention;

fig. 5 is a front view of the hook of the present invention;

FIG. 6 is a partial cross-sectional view of the hook of FIG. 5;

FIG. 7 is a vertical cross-sectional view of the hook of FIG. 5 (with the latch hidden);

reference numerals: 1-beam, 11-slide rail, 2-positioning component, 21-slide block frame, 22-fixed pulley, 23-fixed pin, 24-supporting frame, 3-lifting rope, 4-sling, 41-limiting piece, 5-lifting lug, 6-lifting hook, 61-lifting ring, 62-fixed seat, 63-power unit, 64-hoop unit, 65-clamping block and 7-limiting slide block.

Detailed Description

The present invention will be described in detail with reference to the drawings, which are provided for illustrative and explanatory purposes only and should not be construed as limiting the scope of the present invention in any way. Furthermore, features from embodiments in this document and from different embodiments may be combined accordingly by a person skilled in the art from the description in this document.

Example 1

Referring to fig. 1 and 2, the lifting appliance of the prefabricated part in the embodiment is arranged in a production plant of the prefabricated part and comprises a cross beam 1, a positioning assembly 2, a lifting rope 3 and a lifting rope 4. For the convenient laborsaving removal hoist, the hoist is connected with power unit, and wherein power unit fixes on the driving in the factory building, and power unit in this embodiment includes 2 hoist and motor, and the motor drives 2 hoist motions. The upper surface of crossbeam 1 is provided with a plurality of lugs 5, and lifting rope 3 one end is fixed with lugs 5, and the other end is fixed on power unit's hoist, and the motor drives the winding movement to realize lifting rope 3 in the flexible of vertical direction. Still be provided with the even fixed orifices of a plurality of intervals on crossbeam 1, locating component 2 includes slider frame 21, fixed pulley 22 and fixed pin 23, and fixed pin 23 fixes the top of slider frame 21 on the fixed orifices, and fixed pulley 22 fixes the bottom surface at slider frame 21, and 4 middle parts of hoist cable are set up on fixed pulley 22 surface, and both ends are provided with lifting hook 6 respectively. According to the size of the prefabricated part to be lifted and the position of the lifting nail embedded in the prefabricated part, 2 positioning assemblies 2 are fixed on a specified fixing hole in the cross beam 1, then the sling 4 simultaneously penetrates through the fixed pulleys 22 of the 2 positioning assemblies 2, and the two tail ends of the sling 4 are respectively fixed with the lifting hook 6. The setting mode of the lifting hook 6 when a large prefabricated wallboard is lifted is shown in the attached drawing 1, and the width of the prefabricated wallboard is about 3m, so that the positioning component 2 is fixed on the corresponding fixing hole on the cross beam 1 according to the position of a lifting nail pre-embedded in the prefabricated wallboard. Because evenly distributed has a plurality of fixed orificess on crossbeam 1, when the hoist that adopts the prefabricated component in this implementation hoists other kinds of prefabricated components, can be according to the specification and size of prefabricated component, conveniently increase locating component 2 or adjust the position of adjusting locating component 2 on crossbeam 1, realized the commonality and the universality of hoist like this, reduced the frock cost in the mill.

Referring to fig. 1 and fig. 2, on the basis of the present embodiment, in another modified embodiment, a position limiting mechanism is further disposed on the cross beam 1 of the spreader. The limiting mechanism comprises a limiting slide block 7 and a limiting part 41, the limiting slide block 7 is fixed on a fixing hole of the cross beam 1 through a fixing pin 23, a through hole is formed in the bottom side of the limiting slide block 7, the rope penetrates through the through hole, and the limiting part 41 is a sheet-shaped body or a strip-shaped body which is arranged on the sling 4 and larger than the through hole in size, and is a circular ring-shaped sheet-shaped body in the embodiment. In this embodiment, 2 positioning assemblies 2 are disposed on the cross beam 1, and the limiting slide block 7 may be disposed on the cross beam 1 between the 2 positioning assemblies 2. Because the middle part of the sling 4 is erected on the surfaces of the 2 fixed pulleys 22 and is not fixed, when a worker hooks a hanging nail pre-embedded in a prefabricated part by using one of the lifting hooks 6, the movable telescopic part slides on the fixed pulley 22, and the other lifting hook 6 can move upwards to be clamped on the fixed pulley 22 adjacent to the movable telescopic part; set up limit slide 7 on crossbeam 1 next to locating component 2, then set up 2 ring shape lamellar bodies on hoist cable 4, and 2 ring shape lamellar bodies are located limit slide 7's both sides respectively, and when hoist cable 4 took place to remove, ring shape lamellar body card was in limit slide 7 department, has avoided hoist cable 4 to take place excessive displacement towards a direction.

Referring to fig. 1 and 2, on the basis of the present embodiment, in another modified embodiment, the cross beam 1 is an i-shaped steel, and includes a top steel plate, a bottom steel plate and a vertical steel plate connecting the top steel plate and the bottom steel plate, wherein the bottom steel plate is further provided with a slide rail 11. The slider frame 21 of locating component 2 in this embodiment is the hollow box-like body in inside, and its top side set up with crossbeam 1's vertical steel plate size complex lead to the groove, slider frame 21 inside be provided with slide rail 11 complex slider, slider frame 21's roof card is on crossbeam 1's bottom steel sheet, and can remove along slide rail 11. Referring to fig. 3 and 4, in the present embodiment, a plurality of fixing holes are uniformly formed in the vertical steel plate of the cross beam 1, a fixing plate (not labeled) parallel to the vertical steel plate of the cross beam 1 is disposed on the top of the slider frame 21, and a hole for passing the fixing pin 23 is disposed on the fixing plate. The fixing pin 23 passes through the hole on the fixing plate and the fixing hole on the cross beam 1 in sequence to fix the slider frame 21 on the cross beam 1. The bottom surface of the slide block frame 21 is fixed with a pi-shaped supporting frame 24, the fixed pulley 22 is positioned inside the supporting frame 24, and two ends of the shaft of the fixed pulley 22 are fixed on two side plates of the supporting frame 24. The sliding block frame 21 can not fall off the cross beam 1 even if the positioning pin is taken down in the installation process, so that the safety of the lifting appliance is improved; meanwhile, the arrangement of the slide rail 11 and the installation of the positioning component 2 can be conveniently realized by utilizing the structure of the I-shaped steel, the structure is simple, the cost is lower, and the practicability is high.

Referring to the attached fig. 1, the operation of the spreader in this embodiment will be briefly described: firstly, starting a motor to drive a winch to move, and putting down a sling 4 to enable a cross beam 1 to descend to an operable proper height; then, according to the hanging nails pre-embedded in the prefabricated part to be lifted, 2 or more than 2 positioning assemblies 2 are fixed at the corresponding positions of the cross beam 1, and meanwhile, the slings 4 are arranged in the 2 positioning assemblies 2; then, the lifting hooks 6 at the two ends of the sling 4 are respectively hooked on the lifting nails in the prefabricated part; and finally, starting the motor to drive the winch to move, slowly retracting the lifting rope 3, and hoisting the prefabricated part.

Referring to fig. 5 to 7, the hook 6 in this embodiment is used in cooperation with a hanging nail pre-embedded in a prefabricated member, and the specific structure includes: the lifting ring 61 is positioned at the top side and is in a C shape, the fixed seat 62, the power unit 63 fixed at the top side of the fixed seat 62, the adjusting piece arranged in the fixed seat 62 and the hoop unit 64 connected with the bottom end of the adjusting piece. The bottom end of the hoop unit 64 extends out of the bottom side of the fixing seat 62, the bottom end structure of the hoop unit 64 is matched with the end heads of the hanging nails, and the bottom end of the hoop unit 64 buckles the hanging nails pre-buried in the prefabricated member during use, so that the prefabricated member is hung. The power unit 63 is a cylinder mechanism in this embodiment. In other embodiments, the power unit 63 is one of an air cylinder or an electric cylinder, the lifting ring 61 may not be provided, the two lifting lugs 5 are symmetrically provided on the outer wall of the fixing seat 62, and when in use, the two lifting lugs 5 are respectively penetrated by a steel wire rope.

Referring to fig. 7, which is a cross-sectional view of the hook 6 taken along the central axis of the hanging ring 61, both ends of the hanging ring 61 are symmetrically fixed to both sides of the side wall of the fixing base 62. The fixed seat 62 is enclosed by a top plate, a bottom plate and a side wall connecting the top plate and the bottom plate to form a similar cylinder shape; the top plate and the bottom plate are respectively provided with an upper hole and a lower hole. The power unit 63 includes an oil cylinder and a push rod. Wherein the oil cylinder is arranged on the top side of the fixed seat 62, the push rod is arranged on the bottom side of the oil cylinder, and the push rod extends into the inner space of the fixed seat 62 from the upper hole. The perimeter of the middle section of the adjusting piece is smaller than the perimeter of the two ends, and an hourglass shape with a thin middle part and thick two ends is formed. In this embodiment, the top end of the adjusting member is further provided with a horizontally extending plate, the extending plate is located inside the fixing seat 62, and the diameter of the extending plate is smaller than the inner diameter of the fixing seat 62. The bottom end of the push rod is fixed on the extension plate through a bolt, and the top end of the adjusting piece is also fixed on the extension plate through a bolt. So arranged, a connection between the power unit 63 and the adjustment member is achieved.

With continued reference to fig. 7, the hoop unit 64 includes at least two hoop blocks and a ring-shaped spring surrounding the peripheries of all the hoop blocks; the fixed end of the hoop unit 64 is located above the base plate, and the free end extends out of the lower hole of the base plate. Referring to the schematic drawing, the hoop units 64 enclose to form a cavity with a variable diameter. Staple bolt piece upper portion is the stiff end, and the lower part is the free end, and the stiff end periphery is equipped with the recess, and the below of recess is equipped with the step. The width of the fixed end of the upper part of the hoop block is smaller than that of the free end of the lower part, and the fixed end and the free end of the hoop block are in smooth radian transition. The annular springs are arranged in the grooves of the plurality of hoop blocks; the step is clamped above the bottom plate of the fixed seat 62, so that the fixed end of the hoop unit 64 is clamped inside the fixed seat 62; the end of the free end far away from the fixed end is provided with a pawl matched with the hanging nail. When all the hoop blocks are tightly hooped together through the annular springs on the periphery, the free end side faces of the adjacent hoop blocks are attached together, and the fixed ends of the adjacent hoop blocks cannot be attached to each other due to the fact that the width of the fixed ends is smaller than that of the free ends, so that gaps are formed between the adjacent hoop blocks. The free ends of adjacent hoop blocks form a fulcrum at the contact point of the bottom side of the gap. The annular spring cramps in the stiff end outside, and when annular spring carried out the elastic deformation that contracts, adjacent hoop piece stiff end will take place the motion of being close to in opposite directions, and the width on breach top side reduces gradually this moment, and then adjacent hoop piece free end will carry out opposite away from the motion with the fulcrum of breach bottom side, leads to the pawl to carry out the action of opening. When the annular spring is subjected to stretching elastic deformation, the fixed ends of the adjacent anchor ear blocks are changed from a state of being close to each other to a state of being separated from each other, the width of the top side of the notch is gradually widened, and the free ends of the adjacent anchor ear blocks are close to each other by using the supporting points of the bottom sides of the notches until the free ends of the adjacent anchor ear blocks are restored to a state of being attached to each other, so that the pawls perform a closing action.

Referring to fig. 6, in the present embodiment, a fixture block 65 is further disposed on the fixing base 62, one end of the fixture block 65 is fixed to the fixing base 62, and the other end of the fixture block 65 is disposed inside the fixing base 62 and is clamped on the upper surface of the fixing end of the hoop unit 64. The arrangement ensures that the position of the hoop unit 64 inside the fixed seat 62 is relatively stable, the vertical movement or rotation of the fixed end caused by the opening and closing action process of the free end is avoided, and the normal use of the lifting hook 6 is ensured.

Referring to fig. 6 and 7, the adjusting member is clamped in the cavity of the hoop unit 64, and the longitudinal axis of the push rod and the longitudinal axis of the adjusting member are located on the same straight line. The free end of the hoop block unit extends out of the fixed seat 62 from the lower hole; the diameter of the lower hole of the fixed seat 62 is smaller than the whole width of the step of the hoop unit 64 and larger than the minimum width of the hoop unit 64 at the position penetrating through the lower hole. The power unit 63 drives the adjusting piece with a thin middle part and two thick ends to move vertically upwards or downwards in the cavity of the hoop unit 64, and in the process, the diameter of the cavity enclosed by the fixed end of the hoop unit 64 of the annular spring hoop is gradually increased or decreased. The fixed ends of the adjacent hoop blocks are gradually separated or close, the free ends of the adjacent hoop blocks take the contact point at the bottom side of the notch as a fulcrum, and move towards the fixed ends in an opposite trend, so that the pawls at the bottom ends of the free ends are gradually close or separated, and the pawls at the bottom ends of the free ends perform closing or opening actions. Set up like this, when lifting by crane the prefab, can be through the action of the push rod of control power unit 63 for the action of hook 6 automatic execution couple or unhook does not need the manual work to climb the staircase again and carries out couple or unhook action, has improved the operating efficiency of hoist and mount process, has reduced manual operation's potential safety hazard.

Referring to fig. 7, 2 vertical springs are symmetrically arranged on the extension plate, the top ends of the vertical springs are fixed on the top plate, and the bottom ends of the vertical springs are fixed on the extension plate. It can be guaranteed that when power unit 63 breaks down, the vertical spring can pull the extension plate through elastic deformation when tension which cannot be provided to the adjusting piece, so that the adjusting piece is pulled. Especially when the hook 6 has lifted the preform, once the power unit 63 cannot provide power, such as when the electric cylinder is powered off, the adjusting member will fall under the action of gravity under the condition that the power unit 63 cannot provide upward pulling force, so that the pawl of the hoop unit 64 releases the hook, and the hook is unhooked. This would create a significant safety hazard for the operators of the plant, since the mass of the preforms is very large. Therefore, the vertical spring is arranged in the embodiment, so that the adjusting piece can be guaranteed to be pulled when the power unit 63 breaks down, the hanging nail is prevented from being loosened by the pawl of the hoop unit 64, and the safety of the lifting hook 6 is further improved.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (10)

1. The lifting appliance for the prefabricated part is characterized by comprising a cross beam, a positioning assembly, a lifting rope and a sling, wherein a plurality of lifting lugs are arranged on the upper surface of the cross beam, and one end of the lifting rope is fixed with the lifting lugs; the positioning assembly comprises a sliding block frame, a fixed pulley and a fixed pin, the fixed pin fixes the top end of the sliding block frame on the fixed hole, the fixed pulley is fixed on the bottom surface of the sliding block frame, the middle part of a sling is arranged on the surface of the fixed pulley, and lifting hooks are arranged at two ends of the sling respectively.

2. The prefabricated member hanger according to claim 1, further comprising a limiting mechanism, wherein the limiting mechanism comprises a limiting slider and a limiting member, the limiting slider is disposed on the cross beam, a through hole is disposed at a bottom side of the limiting slider, the sling passes through the through hole, and the limiting member is a sheet or a strip disposed on the sling and having a size larger than that of the through hole.

3. The prefabricated spreader of claim 2, wherein the limiting mechanism is fixed to a cross beam between the two positioning assemblies.

4. The prefabricated member hanger according to claim 2, wherein the position-limiting slider is fixed to the fixing hole by a fixing pin.

5. The prefabricated member hanger according to claim 1, wherein the cross beam is provided with slide rails, and the slider frame is provided with sliders matched with the slide rails.

6. The prefabricated member hanger according to claim 4, wherein the slider frame is a box structure with a hollow interior, the top of the slider frame extends upwards to form a fixing plate, and the fixing plate is provided with holes for the fixing pins to pass through.

7. The prefabricated member hanger according to claim 5, wherein a pi-shaped support frame is fixed to the bottom surface of the slider frame, the fixed pulley is located inside the support frame, and two ends of a shaft of the fixed pulley are fixed to two side plates of the support frame.

8. The prefabricated member hanger according to any one of claims 1 to 7, wherein said hook comprises a fixing base, a power unit, an adjusting member and a hoop unit; the power unit is fixedly connected with the fixing seat, the fixed end of the hoop unit is clamped on the fixing seat, the power unit drives the adjusting piece to move vertically, and the adjusting piece drives the free end of the hoop unit to open or close.

9. The prefabricated member hanger according to claim 8, wherein the fixing base is further provided with a clamping block, one end of the clamping block is fixed on the fixing base, and the other end of the clamping block is arranged in the fixing base and clamped on the upper surface of the fixing end of the hoop unit.

10. The prefabricated member hanger according to claim 9, wherein the power unit comprises a push rod, the middle section of the adjusting member has a circumference smaller than the circumferences of the two ends, and the top end of the adjusting member is connected with the push rod; the hoop unit is enclosed at the outer edge of the adjusting piece and comprises at least two hoop blocks and annular springs enclosed at the peripheries of the hoop blocks, the width of the fixed end of the hoop unit is smaller than that of the free end, the annular springs are arranged at the peripheries of the fixed end, and the bottom end of the free end is provided with a pawl; the push rod of the power unit drives the adjusting piece to vertically move in the hoop unit, and free ends of adjacent hoop blocks are driven to be separated or folded, so that the pawl performs opening or folding actions.

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