CN210032559U

CN210032559U - Servo-triggering anti-falling device for attached lifting scaffold

Info

Publication number: CN210032559U
Application number: CN201920054405.1U
Authority: CN
Inventors: 张立军; 吕瑞亭; 张世元; 李进锋
Original assignee: Shandong Taiyi Metal Science & Technology Co Ltd
Current assignee: Shandong Taiyi Metal Science & Technology Co Ltd
Priority date: 2019-01-14
Filing date: 2019-01-14
Publication date: 2020-02-07
Anticipated expiration: 2029-01-14

Abstract

A servo-triggering anti-falling device of an attached lifting scaffold comprises a fixed steel beam and a guide rail, wherein the servo-triggering anti-falling device and an unloading device are arranged inside the fixed steel beam, the servo-triggering anti-falling device comprises a shaft sleeve, a clamping plate, a balance weight and a servo trigger, the clamping plate, the balance weight and the servo trigger are arranged on the shaft sleeve, the clamping plate, the balance weight and the servo trigger are wound on the outer circular surface of the shaft sleeve and are welded and fixed with the shaft sleeve, a limiting rod with a limiting effect is arranged on the fixed steel beam, the clamping plate and the servo trigger are close to one side of the guide rail, the servo trigger comprises a support fixedly welded with the shaft sleeve, and a swing rod and an elastic pin which are arranged on the support, the anti-falling device is applied to a vertically lifting object, the object is provided with a sliding guide rail, an anti-falling, can brake within the limited fall range to stop falling.

Description

Servo-triggering anti-falling device for attached lifting scaffold

Technical Field

The utility model belongs to the technical field of the building construction tool technique and specifically relates to exactly an inserted lift scaffold servo triggering anti-falling device.

Background

In the JGJ202-2010 construction tool type scaffold safety technical specification, the anti-falling device specified for the attached lifting scaffold must be a mechanical full-automatic device, and a manual device which needs to be reassembled every time the scaffold is lifted is strictly forbidden. The braking distance is not more than 80 mm.

The existing anti-falling device can be divided into two types from the braking form, one type is friction braking, and the other type is blocking braking. The friction braking has the advantage of small braking impact, and the blocking braking has the advantage of short braking distance. The specification has clear requirements on the braking distance, the friction anti-falling device is basically eliminated, and the blocking braking is the main anti-falling device. The core technology of the anti-falling device in the blocking form is an anti-falling triggering technology, and the triggering reliability is the central importance, namely the anti-falling device cannot be triggered without error. All triggers are rigid triggers at present, and the rigid triggers exist and do not trigger or trigger the card to die, and the card that triggers can influence normal decline, does not trigger and can lose the anti-falling function. Both of the above problems are due to the small range of trigger variables (narrow process window). In practical engineering, the guide rail is slightly inclined after the scaffold is stressed, and the inclination enables the falling prevention block on the guide rail to collide with the external part of the trigger block to change when the scaffold descends. The position of the lower anti-falling point is close to the rotating center, so that the lower anti-falling point is blocked; the upper anti-falling point is far away from the rotation center, so that the triggering is not performed.

Disclosure of Invention

An object of the utility model is to provide an inserted lift scaffold frame servo trigger anti-falling device, this anti-falling device are applied to the object of vertical lift, and the object has sliding guide, has on the guide rail to prevent weighing down the piece, if the object lift process when falling by accident appears, can be at the braking of limited fall within range, and the termination falls.

The utility model provides a technical scheme that its technical problem adopted is: the utility model provides an attached lifting scaffold frame servo trigger anti-falling device, includes fixed girder steel 1 and

guide rail

5, 1 inside servo trigger anti-falling device 3 and the unloading device 4 of being provided with of fixed girder steel, servo trigger anti-falling device 3 include axle sleeve 11 and install cardboard 9, counter weight 8 and servo trigger 12 on axle sleeve 11, axle sleeve 11 install on fixed axle 10, cardboard 9, counter weight 8 and servo trigger 12 encircle axle sleeve 11's excircle face and with axle sleeve 11 welded fastening fixed girder steel 1 on be provided with gag lever post 7 that plays limiting displacement, cardboard 9 and servo trigger 12 be close to guide rail 5 one side, servo trigger 12 include with axle sleeve 11 fixed welded support 13 and install pendulum rod 14 and bullet round pin 16 on support 13.

Preferably, the clamping plate 9 is of a rectangular structure, the head of the clamping plate 9 is of a wedge-shaped structure, and one end of the clamping plate 9 is welded with the shaft sleeve 11.

Preferably, a plurality of clamping blocks 6 distributed at equal intervals are arranged on the guide rail 5, and the clamping blocks 6 are welded and fixed with the guide rail 5.

Preferably, the support 13 is welded and fixed with the shaft sleeve 11, the support 13 is composed of a U-shaped groove and a hexagon bolt, and a shaft hole for installing the swing rod 14 is formed in the U-shaped groove of the support 13.

Preferably, the swing rod 14 is of a rectangular structure, the swing rod 14 is movably connected with the support 13 through a rotating shaft 15, and an inclined plane is arranged at the head of the swing rod 14.

Preferably, the elastic pin 16 is in threaded connection with a hexagonal nut on the support 13, and the elastic pin 16 is locked by a lock nut 17.

Preferably, the counterweight 8 is fixedly installed on the counterweight plate through bolts, and the counterweight plate is welded and fixed with the shaft sleeve 11.

Preferably, the elastic pin 16 is connected to the support 13 in a threaded manner, and the elastic pin 16 is attached to the swinging rod 14, and the swinging rod 14 can rotate along the rotating shaft 15 towards the card board 9 side.

Preferably, the length of the clamping plate 9 is greater than that of the swinging rod 14.

The utility model has the advantages that: compared with the prior art, the utility model discloses a servo anti-falling device that triggers of inserted lift scaffold, servo trigger technique adopts servo trigger structure, pendulum rod wedge head structure and assembled counter weight structure. The problems of jamming and no triggering are solved; the swing rod is in a wedge-shaped structure, so that the distance between the clamping plate and the guide rail is reduced, and the stress structure of the clamping plate is improved; the assembly type counterweight structure optimizes the resetting speed of the clamping plate and reduces the braking distance. The servo triggering anti-falling device adopts a triggering signal amplification technology and a servo close following technology, and the triggering process is maintained in a wider range; the trigger signal amplification utilizes the relationship of angular displacement, radius and chord length, namely the principle of proportional amplification. The collected signal is put at a small radius, and the output (utilized) signal is put at a large radius to have a large displacement interval; the servo following technology utilizes the physical property of an elastic element, the elasticity is equal to the external force applied in a dynamic load environment, and the elastic element can be attached to a force application body in a constant way; the servo triggering anti-falling device also adopts a wedge-shaped swing rod head and an assembled counterweight technology. The wedge head swing rod technology can shorten the braking distance, the assembly type balance weight can adjust the resetting speed of the clamping plate, the running safety of the attached scaffold is improved, the phenomenon of illegal operation adopted by a construction site for solving problems is avoided, and the processing cost of parts of the anti-falling device is reduced.

Drawings

FIG. 1 is a general structure diagram of the present invention;

FIG. 2 is an enlarged view of part A of the present invention;

FIG. 3 is a structural diagram of the servo-triggering anti-falling device of the utility model;

FIG. 4 is a diagram of the servo trigger starting operation state of the present invention;

FIG. 5 is a diagram of the compression working state of the spring pin of the present invention;

FIG. 6 is a diagram of the maximum compression operating state of the spring pin of the present invention;

FIG. 7 is a diagram of the working state of the present invention immediately before the end of the servo trigger;

fig. 8 is a diagram of the servo trigger end operating state of the present invention;

FIG. 9 is a state diagram of the falling prevention device of the present invention in normal falling;

FIG. 10 is a schematic view of the locking body of the present invention;

FIG. 11 is an enlarged view of the structure of the servo trigger of the present invention;

fig. 12 is an exploded view of the structure of the servo trigger of the present invention;

the device comprises a fixed steel beam 1, a wall penetrating bolt 2, a servo triggering anti-falling device 3, an unloading device 4, a guide rail 5, a clamping block 6, a limiting rod 7, a balance weight 8, a clamping plate 9, a fixed shaft 10, a shaft sleeve 11, a servo trigger 12, a support 13, a swing rod 14, a rotating shaft 15, a spring pin 16 and a locking nut 17.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

The utility model provides an attached lifting scaffold frame servo trigger anti-falling device, includes fixed girder steel 1 and

guide rail

In the embodiment shown in fig. 1, the scaffold is provided with a guide rail for lifting a heavy object, the guide rail is lifted from a lower position to be higher than the heavy object along with a lifting device, the guide rail is provided with a plurality of clamping blocks, the clamping blocks and the servo-triggering anti-falling device form an anti-falling effect, the servo-triggering anti-falling device is arranged on one side of the guide rail and is fixedly arranged on a wall body or a fixed support, and the guide rail is locked when falling instantly, so that accidents are prevented.

In fig. 2, the servo-triggering anti-falling device is movably mounted inside the fixed steel beam through a fixed shaft, a limiting rod is further arranged on the fixed steel beam, the limiting rod can limit the servo-triggering anti-falling device in the rotating direction and prevent over-rotation, the servo-triggering anti-falling device is composed of a plurality of parts, a middle shaft sleeve is mounted on the fixed shaft, a lubricant is arranged between the shaft sleeve and the fixed shaft to reduce the rotating friction force between the shaft sleeve and the fixed shaft, an unloading device is further arranged on the fixed steel beam, when the guide rail is in a locking state, the guide rail is pulled upwards through the unloading device, the servo-triggering anti-falling device is separated from a clamping block at the upper end of the guide rail, the unloading operation is realized, and the.

In the embodiment shown in fig. 3, fig. 3 is a schematic structural diagram of a servo-triggering anti-falling device, in which the servo-triggering anti-falling device mainly includes a clamping plate, servo triggers and a counter weight, the clamping plate, the servo triggers and the counter weight are arranged on the circumference of a shaft sleeve, the three are uniformly distributed around the circumference of the shaft sleeve, the clamping plate is in a square structure, the clamping plate rotates along with the rotation of the shaft sleeve, the servo triggers adjacent to the clamping plate are welded on the shaft sleeve, the servo triggers include a support, the support is welded and fixed with the shaft sleeve, a swing rod is also arranged on the support through a rotating shaft, an elastic pin for jacking up the swing rod is arranged at the lower end of the swing rod, the elastic pin is locked and fixed through a locking nut, the shaft sleeve is also provided with the counter weight for forming gravity balance between the clamping plate and the servo triggers, the counter weight rotates counterclockwise, the fixture block can press the swing rod on the servo trigger downwards, the swing rod rotates clockwise along the fixed shaft, the elastic pin is compressed, the guide rail continues to move downwards, when the elastic pin is compressed to the maximum, the servo trigger also rotates along the fixed shaft, the shaft sleeve also rotates to drive the clamping plate to rotate, the clamping plate rotates to be in contact with the guide rail, the top end of the clamping plate is positioned between two fixture blocks on the guide rail, the fixture block cannot be in contact with the fixture block on the guide rail at the moment, the locking effect on the guide rail cannot be generated, after the fixture block passes through the servo trigger, the fixture block cannot generate downward force on the servo trigger, meanwhile, the counterweight on the shaft sleeve can rotate anticlockwise along the fixed shaft under the action of gravity, the clamping plate is driven to rotate, the top end of the clamping plate breaks away from the position between the fixture blocks along with the continuous downward movement of the guide rail at the moment, the fixture block, the moving speed of the guide rail is stable and within a normal range of values.

Fig. 4 is servo trigger and begins operating condition picture, in fig. 4, along with the decline of guide rail, fixture block on the guide rail also together descends, the fixture block that is close to the pendulum rod then forms decurrent power to the pendulum rod, the pendulum rod is rotatory along the fixed axle, the axle sleeve also clockwise rotation along the fixed axle simultaneously, the axle sleeve drives the cardboard rotatory, the cardboard is then continuous near the guide rail, it has the fixture block of a plurality of equidistant settings to distribute on the guide rail, the fixture block that is close to the cardboard is continuous with the cardboard top is close to.

FIG. 5 is a view showing the state of the compression of the elastic pin; along with the continuation decline of guide rail, the fixture block on the guide rail also together descends, cardboard and guide rail contact this moment, the cardboard can not continue to rotate along the fixed axle, servo trigger also can not rotate along the fixed axle simultaneously, but this moment, the fixture block that is close to the pendulum rod has not passed through the pendulum rod completely yet, still moving downwards and still continuing to produce decurrent power to the pendulum rod, then the bullet round pin pressurized on servo trigger this moment, the pendulum rod is rotatory along the pivot, lie in the continuous compression of bullet round pin of pendulum rod lower extreme simultaneously, the fixture block on guide rail and the guide rail is continuous moves downwards still.

FIG. 6 is a diagram of the maximum compression state of the spring pin; along with the still continuous downstream of fixture block on guide rail and the guide rail, after the bullet round pin was compressed to the biggest position, the pendulum rod rotated to the position of bottom this moment, no longer continue to rotate along the pivot, continue descending along with the guide rail this moment, fixture block on the guide rail also continues to descend, the fixture block lateral surface that is close to the pendulum rod then is the arc top contact with the pendulum rod, fixture block and pendulum rod friction descend, the cardboard also rubs with the guide rail side simultaneously, the top of cardboard still is located the position between two fixture blocks this moment, the fixture block of upper end also has certain distance on the cardboard top simultaneously, can not contact with the cardboard, just also can not produce locking, this moment, servo trigger anti-falling device is motionless, the guide rail.

FIG. 7 is a diagram illustrating a state of the servo trigger about to end; servo trigger anti-falling device is motionless, and the guide rail continues to descend, is about to break away from with the pendulum rod along with the fixture block that is close to the pendulum rod, under the effect of bullet round pin and counter weight, the pendulum rod along pivot anticlockwise rotation, cardboard and servo trigger device along fixed axle anticlockwise rotation, the fixture block that is close to the pendulum rod this moment can not be to the decurrent power of pendulum rod birth, the fixture block that is close to the cardboard also can not produce decurrent power to the cardboard, under the effect of counter weight, whole anticlockwise rotation.

FIG. 8 is a diagram illustrating a servo trigger end operation state; the servo triggering anti-falling device continues to rotate anticlockwise along the fixed shaft along with the continuous descending of the guide rail, the fixture block close to the swing rod is gradually far away from the swing rod along with the continuous descending, meanwhile, the fixture block close to the swing rod is gradually close to the distance between the fixture block and the clamping plate along with the descending of the guide rail, but the fixture block is not in contact with the clamping plate, the swing rod and the servo trigger continue to rotate anticlockwise along the fixed shaft under the action of the balance weight, and the servo triggering at the moment.

FIG. 9 is a state diagram of normal descent through the fall arrest device; with the continuous decline of guide rail, under the effect of counter weight, pendulum rod and servo trigger continue along fixed axle anticlockwise rotation, the distance between fixture block and the fixture block that is close to the cardboard reaches nearest position, both still have certain distance this moment, but the cardboard at this moment has broken away from the space between two adjacent fixture blocks, also can not produce locking phenomenon between fixture block and the cardboard, the guide rail has passed through anti-falling device this moment, anti-falling device at this moment is under the effect of counter weight, continue anticlockwise rotation, when the cardboard rotates to the position of gag lever post, form spacingly, stop rotating, with the continuous decline of guide rail, the fixture block on the guide rail continues to descend, the fixture block that is close to the cardboard is close to the pendulum rod gradually, just return to producing decurrent power to the pendulum rod, can be according to the state operation of figure 4, begin a new working phase.

When the guide rail normally descends or ascends, the servo-triggering anti-falling device can not lock the guide rail.

However, when the guide rail is in a state of rapid descending, that is, in a state of falling, as shown in fig. 10, when the descending speed of the guide rail is large, when the servo trigger is finished, as shown in fig. 8, the clamping plate rotates counterclockwise along the fixed shaft under the operation of the counterweight, because the descending speed of the guide rail is high and is higher than the rotating speed of the oscillating bar, and when the guide rail descends, the clamping plate does not completely break away from the position between the two clamping blocks, the clamping block at the upper end of the clamping plate contacts with the clamping plate, and as the clamping block continuously descends, the clamping plate is pressed downwards, and the force of the pressing is higher than the gravity of the counterweight, the servo trigger falling prevention device starts the locking operation, the clamping plate stops rotating counterclockwise, the clamping block and the clamping plate form locking, and the guide rail does not continuously descend under the locking effect of the clamping plate.

The clamping plate 9 is of a rectangular structure, the head of the clamping plate 9 is of a wedge-shaped structure, and one end of the clamping plate 9 is welded with the shaft sleeve 11.

The top of cardboard is provided with the wedge structure, also can set up to convex structure, when guide rail normal speed descends, the fixture block that is close to the cardboard is along with the continuous decline of guide rail, the continuous cardboard that is close to of fixture block, and the cardboard is also continuous along fixed axle counter-clockwise turning under the effect of counter weight, the fixture block can contact with the top of cardboard, but because the top of cardboard sets up to wedge or arc, can form the outside power of keeping away from the guide rail to the cardboard when the fixture block constantly descends, outwards release the cardboard, just can not produce fixture block and cardboard locking phenomenon and take place yet.

The guide rail 5 is provided with a plurality of clamping blocks 6 which are distributed at equal intervals, and the clamping blocks 6 are welded and fixed with the guide rail 5.

The fixture block can set up the distance between the fixture block according to the condition of reality, perhaps according to the length of cardboard, under the condition that the guide rail normally descends, servo triggering anti-falling device does not act.

The support 13 is welded and fixed with the shaft sleeve 11, the support 13 is composed of a U-shaped groove and a hexagon bolt, and a shaft hole for installing the swing rod 14 is formed in the U-shaped groove of the support 13.

The U-shaped groove is provided with a shaft hole for installing the swing rod, the swing rod is movably installed on the U-shaped groove through the rotating shaft, and meanwhile, the two sides of the rotating shaft are provided with fixing pins to prevent the swing rod from falling off.

The swing rod 14 is of a rectangular structure, the swing rod 14 is movably connected with the support 13 through a rotating shaft 15, and an inclined plane is arranged at the head of the swing rod 14.

The two ends of the swing rod are provided with arc-shaped structures, the lower end of one side, close to the guide rail, of the swing rod is provided with an inclined plane, the swing rod can rotate along the rotating shaft, the swing rod is arranged inside the U-shaped groove, the lower end face of the swing rod is in contact with the elastic pin, and the elastic pin generates a directional force on the swing rod.

The elastic pin 16 is in threaded connection with a hexagonal nut on the support 13, and the elastic pin 16 is locked by a lock nut 17.

The balance weight 8 is fixedly arranged on the balance weight plate through a bolt, and the balance weight plate is welded and fixed with the shaft sleeve 11.

The fixed steel beam 1 is fixedly connected with the wall body through a wall penetrating bolt 2.

The elastic pin 16 is in threaded connection with the support 13, the elastic pin 16 is attached to the swing rod 14, and the swing rod 14 can rotate towards the card board 9 side along the rotating shaft 15.

The length of the clamping plate 9 is greater than that of the swinging rod 14.

The utility model discloses an attached lifting scaffold servo-triggering anti-falling device, servo-triggering technology adopts servo-triggering structure, pendulum rod wedge-shaped head structure and assembled counter weight structure, has solved the dead and problem of not triggering of card, pendulum rod wedge-shaped structure reduces cardboard and guide rail interval, improves cardboard atress structure, and assembled counter weight has optimized cardboard reset speed, reduces braking distance, and servo-triggering anti-falling device has adopted trigger signal amplification technique and servo following technique, maintains the triggering process in a wider interval scope; the trigger signal amplification utilizes the relationship of angular displacement, radius and chord length, namely the principle of proportional amplification. The collected signal is put at a small radius, and the output (utilized) signal is put at a large radius to have a large displacement interval; the servo following technology utilizes the physical property of an elastic element, the elasticity is equal to the external force applied in a dynamic load environment, and the elastic element can be attached to a force application body in a constant way; the servo triggering anti-falling device also adopts a wedge-shaped swing rod head and an assembled counterweight technology. The wedge head swing rod technology can shorten the braking distance, the assembly type balance weight can adjust the resetting speed of the clamping plate, the running safety of the attached scaffold is improved, the phenomenon of illegal operation adopted by a construction site for solving problems is avoided, and the processing cost of parts of the anti-falling device is reduced.

The above embodiments are only specific cases of the present invention, and the protection scope of the present invention includes but not limited to the product form and style of the above embodiments, any suitable changes or modifications to the device by those of ordinary skill in the art that are consistent with the present invention should fall into the protection scope of the present invention.

Claims

1. The utility model provides an attached lift scaffold servo trigger anti-falling device, includes fixed girder steel (1) and guide rail (5), its characterized in that: a servo trigger anti-falling device (3) and an unloading device (4) are arranged in the fixed steel beam (1), the servo triggering anti-falling device (3) comprises a shaft sleeve (11), a clamping plate (9), a counterweight (8) and a servo trigger (12) which are arranged on the shaft sleeve (11), the shaft sleeve (11) is arranged on the fixed shaft (10), the clamping plate (9), the counterweight (8) and the servo trigger (12) surround the outer circular surface of the shaft sleeve (11) and are welded and fixed with the shaft sleeve (11), a limiting rod (7) with a limiting function is arranged on the fixed steel beam (1), the clamping plate (9) and the servo trigger (12) are close to one side of the guide rail (5), the servo trigger (12) comprises a support (13) fixedly welded with the shaft sleeve (11), and a swing rod (14) and an elastic pin (16) which are arranged on the support (13).

2. The servo-actuated fall arrest device for an attached lifting scaffold of claim 1, wherein: the clamping plate (9) is of a rectangular structure, the head of the clamping plate (9) is of a wedge-shaped structure, and one end of the clamping plate (9) is welded with the shaft sleeve (11).

3. The servo-actuated fall arrest device for an attached lifting scaffold of claim 1, wherein: the guide rail (5) on be provided with a plurality of equidistant distribution fixture block (6), fixture block (6) and guide rail (5) welded fastening.

4. The servo-actuated fall arrest device for an attached lifting scaffold of claim 1, wherein: the support (13) is welded and fixed with the shaft sleeve (11), the support (13) is composed of a U-shaped groove and a hexagon bolt, and a shaft hole for installing the swing rod (14) is formed in the U-shaped groove of the support (13).

5. The servo-actuated fall arrest device for an attached lifting scaffold of claim 1, wherein: the swing rod (14) is of a rectangular structure, the swing rod (14) is movably connected with the support (13) through a rotating shaft (15), and an inclined plane is arranged at the head of the swing rod (14).

6. The servo-actuated fall arrest device for an attached lifting scaffold of claim 1, wherein: the elastic pin (16) is in threaded connection with a hexagonal nut on the support (13), and the elastic pin (16) is locked through a locking nut (17).

7. The servo-actuated fall arrest device for an attached lifting scaffold of claim 1, wherein: the balance weight (8) is fixedly arranged on the balance weight plate through a bolt, and the balance weight plate is welded and fixed with the shaft sleeve (11).

8. The servo-actuated fall arrest device for an attached lifting scaffold of claim 1, wherein: the elastic pin (16) is in threaded connection with the support (13), the elastic pin (16) is attached to the swing rod (14), and the swing rod (14) can rotate towards the clamping plate (9) along the rotating shaft (15).

9. The servo-actuated fall arrest device for an attached lifting scaffold of claim 1, wherein: the length of the clamping plate (9) is greater than that of the swing rod (14).