CN220827146U - Outer automatic hoist that presss from both sides - Google Patents

Abstract

The utility model discloses an outer-clamping type automatic lifting appliance, which belongs to the technical field of lifting and comprises a lifting bracket, a lifting appliance outer pipe, a lifting appliance inner pipe, a spin pipe, a lifting appliance disc, an upper hook claw and a lower hook claw, wherein the lifting bracket is connected with the lifting appliance outer pipe, the spin pipe is sleeved outside the middle upper part of the lifting appliance inner pipe, the lifting appliance outer pipe is sleeved outside the spin pipe, the lifting appliance inner pipe passes through a central through hole of the lifting appliance disc, the outer pipe disc at the lower end of the lifting appliance outer pipe is positioned above the lifting appliance disc, a plurality of upper hook claws are respectively arranged on the lifting appliance disc, a plurality of lower hook claws are respectively arranged at the lower part of the lifting appliance disc, a plurality of clamping blocks are respectively connected between the upper hook claws and the lower hook claws, a plurality of clamping blocks are arranged on the circumferential inner wall of the lifting appliance outer pipe, and the circumferential outer wall of the spin pipe is provided with a short groove, a long groove and a retaining groove, and the clamping blocks can rotate the spin pipe in the process of sequentially arranging the long groove, the retaining groove and the short groove which correspond to each other. The utility model realizes the automatic hoisting function through the pure mechanical parts, and is suitable for operation in severe environments such as long distance, high danger and the like.

Description

Outer automatic hoist that presss from both sides

Technical Field

The utility model belongs to the technical field of hoisting, and particularly relates to a lifting appliance, in particular to an external clamping type automatic lifting appliance.

Background

The non-automatic control lifting appliance generally adopts a hook mode, a hanging belt is hung on the hook, and the hanging belt is tied on an object to be lifted to carry out the object carrying work. The lifting appliance can be hung and detached by manual operation before and after lifting, but is difficult to lift in special environments such as nuclear radiation, high temperature and the like, so an automatic lifting appliance capable of automatically operating before and after lifting is needed, and automatic picking and placing actions are remotely carried out.

The traditional automatic lifting appliance is mostly provided with an electromagnet lifting appliance, namely, the magnetic force of the electromagnet lifting appliance is controlled by controlling the on-off of a power supply of the electromagnet, so that the attraction and the release of the lifted object are controlled, and the automatic lifting appliance has the advantages of remote control and convenient operation, but has the following defects: firstly, only metal objects can be hoisted, and the hoisting machine is not suitable for hoisting nonmetallic objects; secondly, the electric component needs to be connected with a power supply through an electric wire, firstly, the electric component cannot operate if the power supply fails, and secondly, in some special environments, certain risks exist for the electric component, such as in flammable gas environments, and the combustion can be caused by extremely small sparks.

The conventional automatic lifting appliance does not adopt an electromagnet, but the lifting and releasing operations of the lifted object are generally realized by adopting modes such as motor driving and the like, and the defects of adopting electric components or adopting a remote transmission mode for control exist, so that the problems of difficult implementation of a transmission device and the like exist.

Therefore, if the automatic hoisting function without remote transmission can be realized through a pure mechanical part, the various problems can be solved.

Disclosure of utility model

The utility model aims to solve the problems and provide the external clamping type automatic lifting appliance which can realize automatic lifting without adopting electric components or remote transmission.

The utility model realizes the above purpose through the following technical scheme:

The utility model provides an outer clamp type automatic lifting appliance, including the lifting support, still include lifting appliance outer tube, lifting appliance inner tube, spin tube, lifting appliance dish, go up hook and lower hook, the lower extreme of lifting appliance support with vertical lifting appliance outer tube's upper end is connected, vertical spin tube dress is in the top of lifting appliance inner tube and can freely rotate and can not for lifting appliance inner tube vertical movement, lifting appliance outer tube suit is in spin tube is outer, horizontal lifting appliance dish is equipped with central through-hole and lifting appliance inner tube passes this central through-hole, lifting appliance inner tube's lower extreme is to the protruding inner tube dish that forms of periphery direction, the inner tube dish is located lifting appliance dish's lower extreme is to the protruding outer tube dish that forms of periphery direction, the outer tube dish is located lifting appliance dish's top and can not pass lifting appliance dish's central through-hole, in a plurality of upper hook claw that evenly distributed in same circumference is in the lifting appliance outer tube suit is in spin tube's top of spin tube, horizontal spin tube is equipped with central through-hole and the inner tube, horizontal lifting appliance inner tube is equipped with the outer tube is equipped with the boss that the inner tube is located in a plurality of circular arc-shaped hook, a plurality of outer tube diameter of outer tube face down, a plurality of circular-down hook is located in the same circumference respectively around the outer tube around a plurality of boss, a plurality of outer tube circular arc-shaped hook claw are located in the outer tube face down the same circumference respectively and are evenly around the outer tube is located down, a plurality of boss is located in the outer tube has the circular boss, a plurality of boss diameter is located down, and is located down tube respectively, and is located down through the outer tube has the boss diameter, respectively down tube and is evenly down tube, the middle part of the lower end of each circular arc-shaped lug is provided with an upward concave short groove, a vertical long groove is formed between two adjacent circular arc-shaped lugs, the transverse width of the long groove is larger than that of each clamping block, the upper end of the short groove is positioned below the upper end of the long groove, the lower part of the circumferential outer wall of the spin tube is provided with a convex ring protruding towards the peripheral direction, the upper end of the convex ring is uniformly provided with a plurality of lower convex teeth along the peripheral direction, a blocking groove is formed between two adjacent lower convex teeth, and each clamping block can rotate the spin tube in the process of sequentially arranging the corresponding long groove, the blocking groove and the short groove. In order to enable enough movable space to be formed between the suspended end part of the upper hook and the outer pipe disc, a plurality of upper hooks are respectively arranged on the upper surface of the lifting tool disc through a plurality of hook seats, and a plurality of upper hooks are respectively arranged on a plurality of hook seats through transverse upper pin shafts; in addition, the lower end of the lifting bracket is preferably welded with the upper end of the outer pipe of the lifting appliance.

Preferably, in order to better realize the linkage function between the clamping block and the spin tube, the surfaces of the upper side and the lower side of the clamping block are inclined planes and form an eight shape, the parts, located on the two sides of the corresponding short groove, of the circular arc-shaped convex blocks form upper convex teeth, the surfaces of the two transversely opposite sides of the upper convex teeth are inclined planes and vertical planes respectively, the surfaces of the two transversely opposite sides of the lower convex teeth are inclined planes respectively, the right lower part of the long groove and the right lower part of the short groove correspond to one inclined plane of a certain lower convex tooth respectively, and the right upper part of the blocking groove corresponds to the inclined plane of a certain upper convex tooth.

Preferably, in order to achieve the limit function of the spin tube and facilitate processing and assembly, the upper end of the long groove extends to the upper end of the spin tube and is provided with an opening, the upper end of the inner tube of the lifting appliance is provided with an external thread, a limit nut is sleeved at the upper end of the inner tube of the lifting appliance, the circumferential outer wall of the inner tube of the lifting appliance is positioned above the inner tube disc and below the spin tube, a section of outer diameter is increased, an annular step is formed at the position of change of the outer diameter, and the upper end and the lower end of the spin tube are limited by the limit nut and the annular step respectively.

Preferably, in order to realize a linkage function between the upper and lower claws and maintain a downward rotation stress, the linkage comprises a connecting rod and a tension spring, wherein the upper end of the connecting rod is rotatably connected with the corresponding cantilever of the upper claw, the lower end of the connecting rod is rotatably connected with the corresponding cantilever of the lower claw, the upper end of the tension spring is connected with the upper portion of the corresponding connecting rod, and the lower end of the tension spring is connected with the hanger plate.

The utility model has the beneficial effects that:

According to the utility model, through designing the mutually matched lifting bracket, the lifting outer pipe, the lifting inner pipe, the spin pipe, the lifting disk, the upper hook claw and the lower hook claw, when the lifting device is used, the lifting bracket is driven to move up and down only through the lifting arm, the lower hook claw is downwards rotated to be opened and placed at the periphery of the upper end of a lifted object, the upper hook claw is upwards rotated on the outer pipe disk, the lifted object is clamped from the outside, the lifting and transferring the lifted object, the lower hook claw is downwards rotated to be opened by the lifting bracket, the lower hook claw is upwards rotated to be separated from the lifted object by the lifting bracket, the hanging and releasing operations between the whole lifting device and the lifted object are automatically completed through the lifting bracket, the automatic lifting function without electric components and a remote transmission structure is realized through pure mechanical components, the electric risk is avoided, the lifting device is convenient to implement, the lifting device is suitable for long-distance and high-risk and other severe environments and the operation risk is reduced.

Drawings

FIG. 1 is a perspective view of an external clip-on automatic spreader of the present utility model, further illustrating a suspended object;

FIG. 2 is a semi-sectional perspective view of the external clip-on automatic spreader of the present utility model, further illustrating the suspended object;

FIG. 3 is a semi-sectional perspective view of a lifting bracket and outer tube of the spreader of the external clip-on automatic spreader of the present utility model;

FIG. 4 is a perspective view of a spin tube of the external clip-on spreader of the present utility model;

FIG. 5 is one of the perspective views of the outer clip-on automatic spreader of the present utility model, wherein the outer and inner spreader brackets, the outer spreader tube and the inner spreader tube are in a perspective structure;

FIG. 6 is a second perspective view of the outer clip-on automatic spreader of the present utility model, wherein the outer and inner spreader tubes are in a perspective configuration;

Fig. 7 is a third perspective view of the external clamping type automatic lifting appliance in application, wherein the lifting support, the outer lifting appliance pipe and the inner lifting appliance pipe are in perspective structures.

Detailed Description

The utility model is further described below with reference to the accompanying drawings:

As shown in fig. 1 to 7, the external clamping type automatic lifting appliance of the utility model comprises a lifting bracket 1, a lifting appliance outer pipe 2, a lifting appliance inner pipe 12, a spin pipe 14, a lifting appliance disc 4, an upper hook claw 5 and a lower hook claw 10, wherein the lower end of the lifting bracket 1 is welded with the upper end of the vertical lifting appliance outer pipe 2, the vertical spin pipe 14 is sleeved outside the middle upper part of the vertical lifting appliance inner pipe 12 and can freely rotate and can not vertically move relative to the lifting appliance inner pipe 12, the lifting appliance outer pipe 2 is sleeved outside the spin pipe 14, the transverse lifting appliance disc 4 is provided with a central through hole through which the lifting appliance inner pipe 12 passes, the lower end of the lifting appliance inner pipe 12 protrudes towards the peripheral direction to form an inner pipe disc 19, the inner pipe disc 19 is positioned below the lifting appliance disc 4 and can not pass through the central through hole of the lifting appliance disc 4, the lower end of the outer pipe 2 protrudes towards the peripheral direction to form an outer pipe disc 3, the outer tube disc 3 is positioned above the lifting disc 4 and cannot pass through the central through hole of the lifting disc 4, a plurality of upper hooks 5 uniformly distributed on the same circumference are respectively arranged on a plurality of hook seats 7 through transverse upper pin shafts 6, a plurality of hook seats 7 are respectively arranged on the lifting disc 4, a plurality of upper pin shafts 6 surround the periphery of the outer tube disc 3, the suspended end parts of the plurality of upper hooks 5 are all positioned in the area right above the outer tube disc 3, a plurality of lower hooks 10 are respectively arranged at the lower part of the lifting disc 4 through transverse lower pin shafts 18 and are respectively positioned under a plurality of upper hooks 5 in one-to-one correspondence, the suspended end parts are respectively connected through a plurality of linkage devices and have downward synchronous rotation stress, a plurality of raised clamping blocks 20 are uniformly arranged on the circumferential inner wall of the outer tube 2 along the circumferential direction, the upper portion of the circumference outer wall of the spin tube 14 is uniformly provided with a plurality of convex blocks 142 protruding towards the outer circumference direction along the circumference direction, the middle part of the lower end of each convex block 142 is provided with a concave short groove 143, a vertical long groove 141 is formed between two adjacent convex blocks 142, the transverse width of the long groove 141 is larger than that of a clamping block 20, the upper end of the short groove 143 is positioned below the upper end of the long groove 141, the lower portion of the circumference outer wall of the spin tube 14 is provided with a circular convex ring 147 protruding towards the outer circumference direction, the upper end of the convex ring 147 is uniformly provided with a plurality of convex lower convex teeth 145 protruding towards the outer circumference direction, a blocking groove 146 is formed between two adjacent lower convex teeth 145, and the clamping block 20 can rotate the spin tube 14 in the process of sequentially arranging the corresponding long groove 141, the blocking groove 146 and the short groove 143.

As shown in fig. 1-7, the present utility model also discloses a number of more optimal specific structures:

In order to better realize the linkage function between the clamping block 20 and the spin tube 14, the upper and lower side surfaces of the clamping block 20 are inclined planes and form an eight shape, the portions of the circular arc-shaped protruding blocks 142, which are positioned on two sides of the corresponding short grooves 143, form upper protruding teeth 144 protruding downwards, the transversely opposite side surfaces of the upper protruding teeth 144 are inclined planes and vertical planes respectively, the transversely opposite side surfaces of the lower protruding teeth 145 are inclined planes respectively, the right lower part of the long grooves 141 and the right lower part of the short grooves 143 respectively correspond to one inclined plane of a certain lower protruding teeth 145, and the right upper part of the blocking grooves 146 corresponds to the inclined plane of a certain upper protruding teeth 144.

In order to achieve the limiting function of the spin tube 14 and facilitate processing and assembly, the upper end of the long groove 141 extends to the upper end of the spin tube 14 and is opened, the upper end of the inner tube 12 of the lifting appliance is provided with external threads, the limiting nut 13 is sleeved at the upper end of the inner tube 12 of the lifting appliance, a section of the outer wall of the circumference of the inner tube 12 of the lifting appliance, which is positioned above the inner tube disc 19 and below the spin tube 14, is increased in outer diameter, an annular step 15 is formed at the outer diameter change position, and the upper end and the lower end of the spin tube 14 are limited by the limiting nut 13 and the annular step 15 respectively.

In order to realize the linkage function between the upper and lower claws 5 and 10 and maintain the downward rotation stress thereof, the linkage comprises a connecting rod 17 and a tension spring 16, wherein the upper end of the connecting rod 17 is rotatably connected with the cantilever of the corresponding upper claw 5, the lower end of the connecting rod 17 is rotatably connected with the cantilever of the corresponding lower claw 10, the upper end of the tension spring 16 is connected with the upper part of the corresponding connecting rod 17, and the lower end of the tension spring 16 is connected with the sling tray 4.

The outer ring 8 is arranged below the circumferential edge of the lifting disc 4 and is integrally formed, the outer ring 8 is convenient for installing the lower pin shaft 18, meanwhile, the connecting shaft 9 for connecting with the tension spring 16 is convenient to arrange, a plurality of notches are formed in the outer ring 8, and the installation end of the lower hook claw 10, the lower pin shaft 18 and the connecting shaft 9 are all located in the corresponding notches.

As shown in fig. 1-7, when in use, the lifting appliance is suitable for lifting a lifted object 11 with a lifting convex ring at the upper end; firstly, hanging a lifting bracket 1 on a lifting hook 21 at the lower end of a lifting arm (not shown in the figure, the lifting arm is a lifting arm of a conventional crane), lifting the whole automatic lifting tool to hang by utilizing the lifting hook 21, wherein a plurality of clamping blocks 20 of an outer pipe 2 of the lifting tool are respectively positioned in a plurality of short grooves 143 of a spin tube 14, the spin tube 14 and an inner pipe 12 of the lifting tool cannot move downwards, under the action of a tension spring 16, the hanging end part of an upper hook claw 5 and the hanging end part of a lower hook claw 10 are both in a low position (but not in the lowest position), and a plurality of lower hook claws 10 are in an open state, as shown in the figure 5, and a lifting convex ring of a lifted object 11 can enter between the plurality of lower hook claws 10; then the whole lifting appliance is moved to be right above the lifted object 11, the lifted object 11 is placed on the ground or other platforms, then the lifting appliance is moved downwards until a lifting convex ring of the lifted object 11 enters between a plurality of lower hook claws 10 and contacts with the lower surface of an inner pipe disc 19, the lifting appliance is controlled to continue to move downwards, at the moment, under the blocking of the lifted object 11, the lifting appliance inner pipe 12 and the spin pipe 14 move upwards relative to the lifting appliance outer pipe 2, the lower inclined planes of a plurality of clamping blocks 20 of the lifting appliance outer pipe 2 are respectively contacted with the inclined planes of corresponding lower convex teeth 145 on the spin pipe 14, and during the upward movement of the spin pipe 14 relative to the lifting appliance outer pipe 2, the spin pipe 14 automatically rotates (anticlockwise in the drawing) until a plurality of clamping blocks 20 of the lifting appliance outer pipe 2 are respectively placed in a plurality of corresponding blocking grooves 146 on the spin pipe 14, as shown in fig. 6, at the moment, the lifting appliance inner pipe 12 and the spin pipe 14 cannot continue to move upwards relative to the lifting appliance outer pipe 2, and the plurality of lower hook claws 10 are in a completely opened state; then the lifting appliance is controlled to move upwards, the lifting appliance outer pipe 2 moves upwards, and the lifting appliance inner pipe 12, the spin pipe 14, the lifting appliance disc 4 and the lifted object 11 do not move at the beginning, and the suspended end of the upper hook claw 5 and the suspended end of the lower hook claw 10 do not rotate; the outer tube 2 of the lifting appliance continues to ascend, the upper inclined planes of the clamping blocks 20 of the outer tube 2 of the lifting appliance are respectively contacted with the corresponding inclined planes of the corresponding upper convex teeth 144 on the spin tube 14, in the process that the outer tube 2 of the lifting appliance continues to move upwards, the spin tube 14 automatically rotates (anticlockwise in the drawing) until the clamping blocks 20 of the outer tube 2 of the lifting appliance are respectively arranged in the corresponding long grooves 141 on the spin tube 14, in the process, the outer tube disc 3 ascends to drive the suspended end parts of the upper hook claws 5 and the suspended end parts of the lower hook claws 10 to synchronously rotate upwards, the suspended end parts of the lower hook claws 10 hook the lifting convex rings of the lifted object 11, so that the lifted object 11 is clamped until the clamping blocks 20 of the outer tube 2 of the lifting appliance move to the upper parts of the short grooves 143, the upper parts of the lifting convex rings of the lifted object 11 are contacted with the lower surfaces of the inner tube disc 19, or the clamping blocks 20 are blocked by the limit nuts 13, as shown in fig. 7, and the lifted object 11 is reliably clamped at the moment; then, the lifting appliance is controlled to continue to move upwards to lift the lifted object 11 to hang and move to other positions, then, the lifting appliance is controlled to continue to move downwards until the lifted object 11 is placed on the ground or other platforms, the lifting appliance continues to move downwards, because the lifted object 11, the lifting appliance inner tube 12, the spin tube 14 and the lifting appliance tray 4 cannot continue to move downwards, the lifting appliance outer tube 2 moves downwards relative to the spin tube 14, lower inclined planes of a plurality of clamping blocks 20 of the lifting appliance outer tube 2 are respectively contacted with inclined planes of corresponding lower convex teeth 145 on the spin tube 14, and during the continuous descending of the lifting appliance outer tube 2 relative to the spin tube 14, the spin tube 14 automatically rotates (anticlockwise in the drawing) until a plurality of clamping blocks 20 of the lifting appliance outer tube 2 are respectively placed in a plurality of corresponding blocking grooves 146 on the spin tube 14, and at the moment, a plurality of lower hook claws 10 are in a completely opened state; then the lifting appliance is controlled to move upwards, the lifting appliance outer tube 2 moves upwards, the upper inclined planes of the clamping blocks 20 of the lifting appliance outer tube 2 are respectively contacted with the corresponding inclined planes of the corresponding upper convex teeth 144 on the lifting appliance outer tube 14, the lifting appliance outer tube 2 automatically rotates (anticlockwise rotates in the drawing) in the process of continuing to move upwards until the clamping blocks 20 of the lifting appliance outer tube 2 are respectively arranged in the corresponding short grooves 143 on the lifting appliance outer tube 14, as shown in fig. 5, and at the moment, the lifting convex rings of the lifted object 11 can be separated from the lower hook claws 10; the lifting appliance is controlled to move upwards continuously, the whole lifting appliance can move upwards until the lifting convex ring of the lifted object 11 is separated from the plurality of lower hook claws 10, the unhooking operation and the whole lifting process of the lifted object 11 are completed, and the lifting appliance is reset to the state shown in fig. 5 and is ready for the next lifting operation.

The above embodiments are only preferred embodiments of the present utility model, and are not limiting to the technical solutions of the present utility model, and any technical solution that can be implemented on the basis of the above embodiments without inventive effort should be considered as falling within the scope of protection of the patent claims of the present utility model.

Claims (4)

1. The utility model provides an automatic hoist of outer clamp formula, includes hoisting support, its characterized in that: the lifting device further comprises a lifting device outer tube, a lifting device inner tube, a lifting device coil, an upper hook claw and a lower hook claw, wherein the lower end of the lifting device support is connected with the upper end of the lifting device outer tube in the vertical direction, the vertical lifting device inner tube is sleeved outside the middle upper part of the lifting device inner tube and can freely rotate and can not vertically move relative to the lifting device inner tube, the lifting device outer tube is sleeved outside the lifting device inner tube, the transverse lifting device coil is provided with a central through hole, the lifting device inner tube penetrates through the central through hole, the lower end of the lifting device inner tube protrudes towards the peripheral direction to form an inner tube coil, the inner tube coil is positioned below the lifting device coil and can not penetrate through the central through hole of the lifting device coil, the lower end of the lifting device outer tube protrudes towards the peripheral direction to form an outer tube coil, the outer tube coil is positioned above the lifting device coil and can not penetrate through the central through hole of the lifting device coil, a plurality of upper hooks uniformly distributed on the same circumference are respectively arranged on the upper surface of the lifting tool disc through transverse upper pin shafts, a plurality of upper pin shafts surround the periphery of the outer tube disc, the suspended end parts of the upper hooks are all positioned in the area right above the outer tube disc, a plurality of lower hooks are respectively arranged on the lower part of the lifting tool disc through transverse lower pin shafts and are respectively positioned under the upper hooks in one-to-one correspondence, the upper hooks and the lower hooks are respectively connected through a plurality of linkage devices, the suspended end parts have downward synchronous rotation stress, a plurality of raised clamping blocks are uniformly arranged on the circumferential inner wall of the outer tube of the lifting tool along the circumferential direction, a plurality of circular arc-shaped convex blocks which are raised towards the outer circumferential direction are uniformly arranged on the upper part of the circumferential outer wall of the spin tube, the middle part of the lower end of each convex block is provided with an upward concave short groove, a vertical long groove is formed between two adjacent circular arc-shaped convex blocks, the transverse width of the long groove is larger than that of the clamping block, the upper end of the short groove is located below the upper end of the long groove, a convex ring protruding towards the peripheral direction is arranged at the lower part of the peripheral outer wall of the spinning tube, a plurality of lower convex teeth are uniformly arranged at the upper end of the convex ring along the peripheral direction, a blocking groove is formed between two adjacent lower convex teeth, and the clamping block can rotate the spinning tube in the process of sequentially arranging the corresponding long groove, the blocking groove and the short groove.

2. The external clip-on automatic spreader of claim 1, wherein: the upper side surface and the lower side surface of the clamping block are inclined planes and form an eight shape, the parts, located on the two sides of the corresponding short groove, of the arc-shaped protruding blocks form upper protruding teeth, the transverse opposite side surfaces of the upper protruding teeth are inclined planes and vertical planes respectively, the transverse opposite side surfaces of the lower protruding teeth are inclined planes respectively, the right lower part of the long groove and the right lower part of the short groove correspond to one inclined plane of the lower protruding teeth respectively, and the right upper part of the blocking groove corresponds to one inclined plane of the upper protruding teeth.

3. The external clip-on automatic spreader of claim 2, wherein: the upper end of the long groove extends to the upper end of the spin tube and is opened, an external thread is arranged at the upper end of the inner tube of the lifting appliance, a limit nut is sleeved at the upper end of the inner tube of the lifting appliance, a section of outer diameter of the outer wall of the circumference of the inner tube of the lifting appliance, which is positioned above the inner tube disc and below the spin tube, is increased, an annular step is formed at the outer diameter change position, and the upper end and the lower end of the spin tube are limited by the limit nut and the annular step respectively.

4. The external clip-on automatic spreader of claim 1, 2 or 3, wherein: the linkage device comprises a connecting rod and a tension spring, wherein the upper end of the connecting rod is in rotary connection with the corresponding cantilever of the upper hook claw, the lower end of the connecting rod is in rotary connection with the corresponding cantilever of the lower hook claw, the upper end of the tension spring is connected with the corresponding upper part of the connecting rod, and the lower end of the tension spring is connected with the lifting appliance disc.