CN115450552B - Combined ladder of workover rig - Google Patents

Abstract

The invention discloses a combined ladder of a workover rig, which comprises the following components: two ladder assemblies and two armrest assemblies; one of the armrest assemblies is arranged on the outer side of the ladder frame of one of the ladder assemblies, and the other armrest assembly is arranged on the front side of the front longitudinal beam of the ladder frame of the other ladder assembly; two telescopic hydraulic cylinders are arranged on the rear longitudinal beam of the ladder frame of the other ladder assembly; one of the ladder assemblies is fixedly provided with a lower sliding sleeve, the other ladder assembly is fixedly provided with an upper sliding sleeve, a front longitudinal beam of a ladder frame of the one ladder assembly is in sliding fit with the upper sliding sleeve, and a rear longitudinal beam of the ladder frame of the other ladder assembly is in sliding fit with the lower sliding sleeve. The invention can fold or unfold through the armrest assembly, and can fold the armrest assembly in the transportation and storage processes, thereby occupying small space and improving the convenience of transportation and storage. Meanwhile, the height of the combined ladder can be adjusted, the combined ladder is suitable for working conditions of different heights, and the combined ladder is convenient to use.

Description

Combined ladder of workover rig

Technical Field

The invention belongs to the technical field of petroleum exploration equipment, and particularly relates to a combined ladder of a workover rig.

Background

The workover rig is a professional petroleum exploration device for drilling and workover, and is mainly used for lifting and lowering drill rods, oil pipes and sucker rods, repairing a well shaft, opening windows and the like.

At present, workover rig ladder is fixed, can only highly use at a operating mode, and the ladder height can't be adjusted, can not satisfy the installation operation requirement of highly adjustable workover platform, and handrail (112) are fixed mounting on the railing seat, and occupation space is great in transportation and the storage process when installing the maintenance ladder, and transportation and storage are very inconvenient.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a combined ladder of a workover rig. The technical problems to be solved by the invention are realized by the following technical scheme:

a combination ladder for a workover rig, comprising: two ladder assemblies and two armrest assemblies;

the ladder assembly includes: the folding driving mechanism comprises a ladder frame, a folding driving mechanism, a synchronous rod, two driving rods and a plurality of step plates arranged on the ladder frame;

one of the armrest assemblies is arranged on the outer side of the ladder frame of one of the ladder assemblies, and the other armrest assembly is arranged on the front side of the front longitudinal beam of the ladder frame of the other ladder assembly;

The ladder frame of one of the ladder assemblies is positioned at the rear side of the ladder frame of the other ladder assembly;

the synchronous rod is connected with the folding driving mechanism, and two ends of the synchronous rod are respectively hinged with one ends of the two driving rods;

the other ends of the two driving rods are respectively hinged with two side parts of the handrail component;

the folding driving mechanism is arranged on the rear longitudinal beam of the ladder frame and is close to the lower end of the ladder frame, and is used for enabling the synchronous rod to drive the two driving rods to move so as to drive the handrail component to fold or unfold;

two telescopic hydraulic cylinders are arranged on the rear longitudinal beam of the ladder frame of the other ladder assembly;

the telescopic hydraulic oil cylinder is parallel to the rear longitudinal beam of the ladder frame, the fixed end is fixedly connected with the part, close to the lower end, of the rear longitudinal beam of the ladder frame of the other ladder assembly, and the telescopic end is fixedly connected with the lower end of the ladder frame of the one ladder assembly;

the front longitudinal beam of the ladder frame of one ladder assembly is fixedly provided with a lower sliding sleeve, the rear longitudinal beam of the ladder frame of the other ladder assembly is fixedly provided with an upper sliding sleeve, the front longitudinal beam of the ladder frame of one ladder assembly is in sliding fit with the upper sliding sleeve, and the rear longitudinal beam of the ladder frame of the other ladder assembly is in sliding fit with the lower sliding sleeve.

In one embodiment of the present invention, the folding driving mechanism includes: the device comprises a cylinder, a supporting plate, a stabilizing plate and two connecting plates;

the armrest assembly includes: two armrest link assemblies;

the armrest link assembly includes: a handrail, a first support rail and a second support rail;

the supporting plate is fixedly connected with the rear longitudinal beam of the ladder frame;

the stabilizing plate is fixedly connected with the rear longitudinal beam of the ladder frame;

the fixed end of the cylinder is fixedly connected with the supporting plate and the stabilizing plate respectively through two L-shaped fixing plates, and the telescopic direction of the cylinder is parallel to the rear longitudinal beam of the ladder frame;

the connecting plate is fixedly connected with the rear longitudinal beam of the ladder frame and provided with a sliding through hole;

the two connecting plates are positioned on two side parts of the ladder frame;

the sliding through hole is a waist-shaped hole, and the long shaft is parallel to the expansion and contraction direction of the air cylinder;

the two ends of the synchronous rod respectively penetrate through the two sliding through holes to be hinged with one ends of the two driving rods, and the two ends of the synchronous rod are in sliding contact with the sliding through holes;

the handrail is parallel to the front longitudinal beam, and two ends of the handrail are respectively and movably connected with the upper end of the first support handrail and the upper end of the second support handrail;

The first support rail is parallel to the second support rail;

the lower ends of the first support rail and the second support rail of one of the handrail components are respectively hinged with the upper end and the lower end of the outer side part of the ladder frame of one of the ladder components;

the lower ends of the first support rail and the second support rail of the other handrail component are respectively hinged with the upper end and the lower end of the front side part of the front longitudinal beam of the ladder frame of the other ladder assembly;

the other ends of the two driving rods are respectively hinged with the rod parts of the second support rails of each handrail connecting rod assembly.

In one embodiment of the invention, the first support rail comprises: the first sleeve, the first telescopic rod and the bending section; the second support rail comprising: a second sleeve and a second telescopic rod;

the lower end of the first sleeve is hinged with the position, close to the upper end, of the outer side part of the ladder frame;

the first telescopic rod penetrates into the first sleeve from the upper end of the first sleeve and is in sliding connection with the first sleeve, and the upper end of the first telescopic rod is fixedly connected with one end of the bending section;

the other end of the bending section extends towards the handrail and is provided with a sliding through hole;

The sliding through hole is a waist-shaped hole, and the long shaft extends along the long shaft direction of the handrail;

one end of the handrail is movably connected with the sliding through hole, and the other end of the handrail is hinged with the upper end of the second telescopic rod;

the second telescopic rod penetrates into the second sleeve from the upper end of the second sleeve and is connected with the second sleeve in a sliding manner;

the lower end of the second sleeve is hinged with the lower end of the outer side part of the ladder frame;

the lower ends of the first sleeve and the second sleeve of one of the handrail components are respectively hinged with the upper end and the lower end of the outer side part of the ladder frame of one of the ladder components;

the lower ends of the first sleeve and the second sleeve of the other handrail component are respectively hinged with the upper end and the lower end of the front side part of the front longitudinal beam of the ladder frame of the other ladder assembly;

the other ends of the two driving rods are respectively hinged with the rod part of the first sleeve of each armrest connecting rod assembly;

wherein, when the armrest connecting rod assembly is unfolded, the long axis of the sliding through hole is parallel to the armrest railing.

In one embodiment of the present invention, a reinforcing rod is further disposed between the first sleeve and the second sleeve;

The reinforcing rod is parallel to the handrail, and two ends of the reinforcing rod are hinged with the first sleeve and the second sleeve respectively.

In one embodiment of the present invention, a plurality of first sliding pin holes sequentially arranged along the long axis direction are respectively formed on the pipe walls of two opposite sides of the first sleeve; the outer walls of the two opposite sides of the first telescopic rod are respectively provided with a first ball spring positioning bead;

the first ball spring positioning bead can slide into or slide out of the first sliding pin hole under the action of external force;

a plurality of second sliding pin holes which are sequentially arranged along the long axis direction are respectively formed on the pipe walls of the two opposite sides of the second sleeve; the outer walls of the two opposite sides of the second telescopic rod are respectively provided with a second ball spring positioning bead;

the second ball spring positioning bead can slide into or slide out of the second sliding pin hole under the action of external force.

In one embodiment of the invention, the synchronizing bar comprises a main bar body and two sliding bars; the diameter of the sliding connection rod is smaller than that of the main rod body;

the two ends of the main rod body are fixedly connected with one ends of the two sliding connection rods respectively;

the other ends of the two sliding connection rods respectively penetrate through the two sliding through holes to be hinged with one ends of the two driving rods, and the two sliding connection rods are in sliding contact with the sliding through holes.

In one embodiment of the present invention, the connection plate includes: a first L-shaped sub-board and a second L-shaped sub-board;

the horizontal section of the first L-shaped sub board is fixedly connected with the rear longitudinal beam of the ladder frame, and the vertical section of the first L-shaped sub board is fixedly connected with the vertical section of the second L-shaped sub board;

the second L-shaped daughter board extends towards the rear of the ladder frame, and the sliding through hole and the rectangular through hole are formed in the vertical section;

the rectangular through hole is positioned above the sliding through hole.

In one embodiment of the invention, the two ladder assemblies include a lower ladder assembly and an upper ladder assembly;

the ladder frame of the lower ladder assembly is a lower ladder frame, and the ladder frame of the upper ladder assembly is an upper ladder frame;

the lower ladder frame is positioned at the rear side of the upper ladder frame;

the lower sliding sleeve is fixedly arranged on the front longitudinal beam of the lower ladder frame, the upper sliding sleeve is fixedly arranged on the rear longitudinal beam of the upper ladder frame, the front longitudinal beam of the lower ladder frame is in sliding fit with the upper sliding sleeve, and the rear longitudinal beam of the upper ladder frame is in sliding fit with the lower sliding sleeve.

In one embodiment of the present invention, the bending section includes: the first bending plate and the second bending plate are symmetrically arranged; the sliding through hole includes: a first sub-via and a second sub-via;

One end of the first bending plate is fixedly connected with the upper end of the first telescopic rod, and the other end of the first bending plate extends towards the handrail;

the second bending plate and the first bending plate are respectively and symmetrically arranged on two sides of the first telescopic rod, one end of the second bending plate is fixedly connected with the upper end of the first telescopic rod, and the other end of the second bending plate extends towards the handrail;

the first sub-through holes are positioned on the first bending plate;

the second sub-through holes are positioned on the second bending plate;

two sides of one end of the handrail are respectively provided with a sliding column;

the two sliding columns are respectively positioned in the first sub through hole and the second sub through hole and are in sliding contact with the first sub through hole and the second sub through hole.

The invention has the beneficial effects that:

according to the invention, the combined ladder structure is formed by the two ladder assemblies and the corresponding handrail assemblies, the handrail assemblies can be folded or unfolded under the drive of the folding driving mechanism, and the handrail assemblies can be folded in the transportation and storage processes when the maintenance ladder is installed, so that the occupied space is small, and the convenience of transportation and storage is improved. Meanwhile, the telescopic hydraulic cylinder can drive one ladder assembly to slide on the other ladder assembly, so that the combined ladder can be lengthened or retracted, the height of the combined ladder can be adjusted, the installation and use requirements of the height-adjustable well repairing platform are met, the combined ladder is suitable for working conditions of different heights, and the combined ladder is convenient to use.

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Drawings

FIG. 1 is a schematic side view of a combined ladder of a workover rig in an extended and deployed state, according to an embodiment of the present invention;

FIG. 2 is a rear side view of a combined ladder of a workover rig according to an embodiment of the present invention in an extended deployed state;

FIG. 3 is a schematic view of a partially enlarged construction of a folding drive mechanism in an extended and deployed state of a combined ladder of a workover rig according to an embodiment of the present invention;

FIG. 4 is a schematic view of a partially enlarged construction of a folding drive mechanism in a rear side view of a combined ladder in an extended deployed state of a workover rig, according to an embodiment of the present invention;

FIG. 5 is a schematic illustration of the folding and unfolding principle of a handle link assembly of a combined ladder of a workover rig according to an embodiment of the present invention;

FIG. 6 is a schematic illustration of a rear side view of a lower ladder assembly in a deployed, extended state of a combined ladder of a workover rig, according to an embodiment of the present invention;

FIG. 7 is a schematic view of a first support rail according to an embodiment of the present invention;

FIG. 8 is a schematic view of the first support rail and handrail engagement provided by an embodiment of the present invention;

FIG. 9 is a schematic illustration of the cooperation of the bending section and the handrail in the folded state of the handrail linkage assembly according to an embodiment of the present invention;

fig. 10 is a schematic structural view of a cylinder and a lower synchronizing rod according to an embodiment of the present invention;

FIG. 11 is a front side view of a combined ladder of a workover rig in an extended deployed state, according to an embodiment of the present invention;

FIG. 12 is a schematic view of a partially enlarged construction at a connection plate of a combined ladder of a workover rig in a front side view in an extended deployed state, according to an embodiment of the present invention;

FIG. 13 is a schematic view of a partially enlarged structure of a lower sliding sleeve and an upper sliding sleeve in a rear side view of a combined ladder in an extended and deployed state of a workover rig according to an embodiment of the present invention;

fig. 14 is a side structural view of a collapsed and folded configuration of a combined ladder of a workover rig according to an embodiment of the present invention.

Reference numerals illustrate:

100-lower ladder assembly; 110-a lower armrest assembly; 111-an armrest link assembly; 112-handrail; 113-a first support rail; 114-a second support rail; 115-skid columns; 120-lower ladder rack; 121-a front side rail of a lower ladder frame; 122-a rear stringer of the lower ladder frame; 130-a fold-down drive mechanism; 131-cylinder; 132-a support plate; 133-stabilising plates; 134-connecting plates; 135-L type fixed plate; 136-a sliding through hole; 140-lower synchronizing bar; 150-a lower active lever; 160-lower step plate; 170-lower sliding sleeve; 171-a first mounting plate; 172-a first sled; 173-a connection; 174-locating pins; 200-upper ladder assembly; 210-an upper armrest assembly; 220-getting up the ladder rack; 221-a front longitudinal beam of an upper ladder frame; 222-a rear stringer of an upper ladder frame; 230-upper fold drive mechanism; 240-up sync bar; 250-upper active lever; 260-upper step plate; 261-fixing pin holes; 270-upper sliding sleeve; 271-a second mounting plate; 272-a second sled; 280-telescopic hydraulic cylinder; 310-a first sleeve; 311-a first telescopic rod; 312-bending sections; 313-a sliding through hole; 314—a first ball spring positioning bead; 315-a first bending plate; 316-a second bending plate; 317-first sub-vias; 318-second sub-vias; 320-a second sleeve; 321-a second telescopic rod; 330-reinforcing bars; 410-a main rod body; 420-a slide bar; 510-a first L-shaped daughter board; 520-second L-shaped daughter board; 521-rectangular through holes.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but embodiments of the present invention are not limited thereto.

Example 1

As shown in fig. 1, 2 and 14, a combined ladder for a workover rig includes: two ladder assemblies and two armrest assemblies; a ladder assembly, comprising: the folding device comprises a ladder frame, a folding driving mechanism, a synchronous rod, two driving rods and a plurality of step plates arranged on the ladder frame. The step plates are sequentially arranged on the ladder frame from top to bottom.

Specifically, two ladder assemblies, one being a lower ladder assembly 100 and the other being an upper ladder assembly 200, are respectively a lower armrest assembly 110 and an upper armrest assembly 210. The lower ladder assembly 100 is identical in construction to the upper ladder assembly 200. The upper ladder assembly 200 includes: an upper ladder frame 220, an upper folding driving mechanism 230, an upper synchronizing bar 240, two upper driving bars 250, and a plurality of upper step plates 260 provided on the upper ladder frame 220. The lower ladder assembly 100 includes: a lower ladder frame 120, a lower folding driving mechanism 130, a lower synchronizing bar 140, two lower driving bars 150, and a plurality of lower step plates 160 provided on the lower ladder frame 120.

One of the armrest assemblies is disposed on an outboard portion of the ladder frame of one of the ladder assemblies and the other armrest assembly is disposed on a front side portion of the front rail of the ladder frame of the other ladder assembly. Specifically, the lower armrest assembly 110 is disposed on the outboard portion of the lower ladder frame 120 of the lower ladder assembly 100 and the upper armrest assembly 210 is disposed on the front side of the front rail 221 of the upper ladder frame of the upper ladder assembly 200. The two handrail components have the same structure and are different from the connecting positions of the two ladder frames respectively.

The ladder frame of one of the ladder assemblies is positioned at a location rearward of the ladder frame of the other ladder assembly. Specifically, the lower ladder frame 120 of the lower ladder assembly 100 is positioned at a location rearward of the upper ladder frame 220 of the upper ladder assembly 200.

The following active lever 150, lower synchronizing lever 140, and lower fold driving mechanism 130 are specifically described as examples in the drawings: the lower synchronizing bar 140 is connected with the lower folding driving mechanism 130, and both ends of the lower synchronizing bar 140 are hinged with one ends of the two lower driving bars 150, respectively. The other end of one of the lower drive links 150 is hinged to one side of the lower armrest assembly 110. The other end of the other lower driving lever 150 is hinged to the other side of the lower armrest assembly 110.

The lower folding driving mechanism 130 is disposed on the rear longitudinal beam 121 of the lower ladder frame, the lower folding driving mechanism 130 is close to the lower end of the lower ladder frame 120, and the lower folding driving mechanism 130 is used for driving the lower synchronizing rod 140 to drive the two lower driving rods 150 to move so as to drive the lower handrail assembly 110 to fold or unfold. The lower folding driving mechanism 130 is used for driving the lower synchronizing rod 140 to drive the lower driving rod 150 to move so as to drive the lower handrail assembly 110 to fold or unfold. Similarly, the upper folding driving mechanism 230, the upper synchronizing lever 240 and the upper driving lever 250 are not described again.

In this embodiment, under the driving of the folding driving mechanism, the synchronizing rod can simultaneously drive the two driving rods to move so as to drive the handrail component to fold or unfold. Specifically, two sides of the handrail assembly are respectively two handrail connecting rod assemblies 111, the two handrail connecting rod assemblies 111 are respectively positioned on the ladder frames at two sides of the step plate (the left side and the right side of the step plate), the two driving rods are positioned at two sides of the step plate, and the other end of each driving rod is hinged with the handrail connecting rod assembly 111 at the corresponding side. Taking the lower folding driving mechanism 130 as an example, the lower synchronizing rod 140 can simultaneously drive the two lower driving rods 150 to move so as to drive the two handrail connecting rod assemblies 111 to fold or unfold synchronously under the driving of the lower folding driving mechanism 130.

Two telescopic hydraulic cylinders 280 are arranged on the rear longitudinal beam of the ladder frame of the other ladder assembly, the telescopic direction of each telescopic hydraulic cylinder 280 is parallel to the rear longitudinal beam of the ladder frame, the fixed end of each telescopic hydraulic cylinder 280 is fixedly connected with the position, close to the lower end, of the rear longitudinal beam of the ladder frame of the other ladder assembly, and the telescopic end of each telescopic hydraulic cylinder 280 is fixedly connected with the lower end of the ladder frame of one ladder assembly. The front longitudinal beam and the rear longitudinal beam of the ladder frame are parallel. Specifically, two telescopic hydraulic cylinders 280 are provided on the rear side rail 222 of the upper ladder frame. The telescopic direction of the telescopic hydraulic cylinder 280 is parallel to the rear longitudinal beam 222 of the upper ladder frame, the fixed end of the telescopic hydraulic cylinder 280 is fixedly connected with the part, close to the lower end, of the rear longitudinal beam 222 of the upper ladder frame, and the telescopic end of the telescopic hydraulic cylinder 280 is fixedly connected with the lower end of the lower ladder frame 120.

The front longitudinal beam of the ladder frame of one ladder assembly is fixedly provided with a lower sliding sleeve 170, the rear longitudinal beam of the ladder frame of the other ladder assembly is fixedly provided with an upper sliding sleeve 270, the front longitudinal beam of the ladder frame of one ladder assembly is in sliding fit with the upper sliding sleeve 270, and the rear longitudinal beam of the ladder frame of the other ladder assembly is in sliding fit with the lower sliding sleeve 170. Specifically, the front longitudinal beam 121 of the lower ladder frame is fixedly provided with a lower sliding sleeve 170, the rear longitudinal beam 222 of the upper ladder frame is fixedly provided with an upper sliding sleeve 270, the front longitudinal beam 121 of the lower ladder frame is in sliding fit with the upper sliding sleeve 270, and the rear longitudinal beam 222 of the upper ladder frame is in sliding fit with the lower sliding sleeve 170. The lower handrail assembly 110 is provided on the outer side of the lower ladder frame 120 and the upper handrail assembly 210 is provided on the front side of the front longitudinal beam 221 of the upper ladder frame. The telescopic hydraulic ram 280 drives the lower ladder assembly 100 to slide over the rear stringers 222 of the upper ladder frame, with the upper rail assembly 210 positioned between the lower rail assemblies 110, and with the lower rail assemblies 110 in spatial movement between the outside of the upper rail assemblies 210, without affecting the sliding of the lower ladder frame assembly over the rear stringers 222 of the upper ladder frame.

In this embodiment, the folding driving mechanism is used to make the synchronizing rod drive the active rod to move so as to drive the armrest assembly to fold or unfold, and the telescopic hydraulic cylinder 280 is used to drive the lower ladder assembly 100 to slide on the upper ladder assembly 200 so as to realize the overall length extension or shortening of the two ladder assemblies, so that the height of the combined ladder can be adjusted. Specifically, as the telescopic hydraulic ram 280 drives the lower ladder assembly 100 to slide on the rear stringers 222 of the upper ladder frame, the lower sliding sleeve 170 moves slidingly on the rear stringers 222 of the upper ladder frame with the lower ladder frame 120, so that the front stringers 121 of the lower ladder frame also move slidingly on the upper sliding sleeve 270, to achieve the extension and retraction of the overall length of the lower ladder assembly 100 and the upper ladder assembly 200, thereby adjusting the length of the combined ladder. In this embodiment, two ladder assemblies and corresponding handrail subassembly constitute the combination ladder structure, under folding actuating mechanism's drive, make the handrail subassembly can fold or expand, when installing the maintenance ladder, can fold the handrail subassembly in transportation and the storage, occupation space is less, has improved transportation and storage's convenience. Meanwhile, one (lower layer) ladder assembly can be driven to slide on the other (upper layer) ladder assembly through the telescopic hydraulic oil cylinder 280, so that the combined ladder can be extended or retracted, the height of the combined ladder can be adjusted, the installation and use requirements of the height-adjustable well repairing platform are met, and the combined ladder is suitable for working conditions of different heights and convenient to use.

When the user uses the combination ladder, the climbing surface of the user is the front side of the ladder frame, and correspondingly, the climbing surface is the rear side opposite to the front side, the longitudinal beam on the front side is the front longitudinal beam, and the longitudinal beam on the rear side is the rear longitudinal beam. The left side and the right side of the step plate are fixed with longitudinal beams, the left side and the right side of the front side are two front longitudinal beams, and the left side and the right side of the rear side are two corresponding rear longitudinal beams.

Example two

As shown in fig. 2, 3 and 4, the present embodiment further defines a folding driving mechanism on the basis of the first embodiment, and includes: a cylinder 131, a support plate 132, a stabilizing plate 133, and two connection plates 134.

The armrest assembly includes: two armrest link assemblies 111. Two armrest link assemblies 111 are located on the left and right sides of the step plate. The two handrail link assemblies 111 of the lower handrail assembly 110 are provided on the outer side portions of both sides of the lower ladder frame 120, respectively. The two armrest link assemblies 111 of the upper armrest assembly 210 are disposed on the front side portions of the two front stringers of the upper ladder frame 220, respectively.

In this embodiment, the lower ladder assembly 100 is taken as an example to describe the detailed description of the specific embodiments, and the same structure of the upper ladder assembly 200 will not be repeated.

An armrest link assembly 111 comprising: a handrail 112, a first support rail 113 and a second support rail 114.

The support plate 132 is fixedly coupled to the rear stringers of the lower ladder frame 120. The stabilizer plate 133 is fixedly coupled to the rear stringers of the lower ladder frame 120. The fixed end of the cylinder 131 is fixedly connected with the support plate 132 and the stabilizing plate 133 through two L-shaped fixing plates 135, respectively, and the telescopic direction of the cylinder 131 is parallel to the rear longitudinal beam 121 of the lower ladder frame. In this embodiment, two L-shaped fixing plates 135 are fixedly connected to the support plate 132 and the stabilizing plate 133, respectively, and the fixed end of the cylinder 131 is fixedly connected to the two L-shaped fixing plates 135.

The connection plate 134 is fixedly connected with the rear longitudinal beam 121 of the lower ladder frame, and a sliding through hole 136 is formed in the connection plate 134. The two connection plates 134 are respectively located on both sides of the ladder frame, and the two connection plates 134 are respectively fixedly connected with the two rear stringers. The sliding through hole 136 is a waist-shaped hole, and the long axis of the sliding through hole 136 is parallel to the expansion and contraction direction of the cylinder 131. Two ends of the synchronizing rod respectively penetrate through the two sliding through holes 136 and are hinged with one ends of the two driving rods, and two ends of the synchronizing rod are in sliding contact with the sliding through holes 136.

The handrails 112 are parallel to the front stringers 121 of the lower ladder frame, and both ends of the handrails 112 are movably connected to the upper ends of the first and second support rails 113 and 114, respectively. The first support rail 113 is parallel to the second support rail 114. The handrail 112, the first and second support rails 113 and 114, and the front stringers 121 of the lower ladder frame form a parallelogram structure when the handrail link assembly 111 is deployed.

The lower ends of the first and second support rails 113, 114 of the other rail assembly are hinged to the upper and lower ends, respectively, of the front side members of the front stringers of the ladder frames of the other ladder assembly. Specifically, the lower ends of the first and second support rails 113 and 114 of the upper handrail assembly 210 are hinged to the upper and lower ends, respectively, of the front side of the front rail 221 of the upper ladder frame.

The other ends of the two drive bars are respectively hinged to the bar portions of the second support rail 114 of each armrest link assembly 111. Specifically, the other end of each lower drive link 150 is hinged to the stem of the second support rail 114 of each armrest link assembly 111, respectively.

In this embodiment, the folding principle of the handrail connecting rod assembly 111 can be simplified as shown in fig. 5, and accordingly, the cylinder 131 is extended to drive the lower synchronizing rod 140 to slide forward, the lower synchronizing rod 140 pushes the lower driving rod 150 to move, the lower driving rod 150 pushes the second supporting rail 114, the angle between the other end of the lower driving rod 150 and the second supporting rail 114 is reduced, the second supporting rail 114 drives the handrail 112 and the first supporting rail 113 to move, and the handrail connecting rod assembly 111 integrally moves upward to be unfolded. Conversely, the cylinder 131 contracts to drive the lower synchronizing rod 140 to slide backward, the lower synchronizing rod 140 pulls the lower driving rod 150 to move, the lower driving rod 150 pulls the second support rail 114, the angle between the other end of the lower driving rod 150 and the second support rail 114 increases, and the armrest connecting rod assembly 111 moves downward as a whole to be folded together.

In this embodiment, the automatic unfolding and folding of the two handrail components can be realized by driving the connecting rod structure through the air cylinder 131, and the handrail components can be folded in the transportation and storage processes when the maintenance ladder is installed, so that the occupied space is small, and the convenience of transportation and storage is improved. Meanwhile, the first support railing 113 and the second support railing 114 of the handrail assembly are hinged with the ladder frame, and can be detached from the ladder frame during installation and maintenance, so that the convenience of installation and maintenance is improved, and the convenience of transportation and storage can be further improved.

Further, as shown in fig. 6, 7, and 11, the first support rail 113 includes: a first sleeve 310, a first telescoping rod 311, and a bending section 312; a second support rail 114 comprising: second cannula 320 and second telescoping rod 321.

The lower end of the first sleeve 310 is hinged to the outer side of the lower ladder frame 120 near the upper end (the lower end of the first sleeve 310 is hinged to the outer side of the rear side member 121 of the lower ladder frame near the upper end). The upper end of the first telescopic rod 311 penetrates into the first sleeve 310 from the upper end of the first sleeve 310, the first telescopic rod 311 is in sliding connection with the first sleeve 310, and the upper end of the first telescopic rod 311 is fixedly connected with one end of the bending section 312. The other end of the bending section 312 extends toward the handrail 112, and a sliding through hole 313 is formed in the bending section 312. The sliding through hole 313 is a waist-shaped hole, and a long axis of the sliding through hole 313 extends along the long axis direction of the handrail 112. One end of the handrail 112 is movably connected with the sliding through hole 313, and the other end of the handrail 112 is hinged with the upper end of the second telescopic rod 321.

The second telescopic rod 321 penetrates into the second sleeve 320 from the upper end of the second sleeve 320, and the second telescopic rod 321 is in sliding connection with the second sleeve 320. The lower end of the second sleeve 320 is hinged to the outer side of the ladder frame near the lower end (the lower end of the second sleeve 320 is hinged to the outer side of the rear side member 121 of the lower ladder frame near the lower end).

The lower ends of the first and second bushings 310 and 320 of the other rail assembly are hinged to the upper and lower ends of the front side members of the front stringers of the ladder frame of the other ladder assembly, respectively. Specifically, the lower ends of the first and second bushings 310 and 320 of the upper handrail assembly 210 are hinged to the upper end of the front side portion of the front side member 221 of the upper ladder frame and the lower end of the front side portion of the front side member 221 of the upper ladder frame, respectively. The other ends of the two lower driving levers 150 are respectively hinged to the lever portions of the first bushings 310 of each armrest link assembly 111.

Wherein the long axis of the sliding through hole 313 is parallel to the handrail 112 when the handrail link assembly 111 is deployed.

In this embodiment, the first telescopic rod 311 can move telescopically in the first sleeve 310 under the action of external force, and the second telescopic rod 321 can move telescopically in the second sleeve 320 under the action of external force, so that the folded volume of the armrest connecting rod assembly 111 is smaller. Specifically, when the armrest link assembly 111 is folded, the first and second telescopic links 311 and 321 are manually operated to retract into the first and second bushings 310 and 320, respectively, by a certain length, and the folded length of the armrest link assembly 111 is relatively shorter, thereby reducing the folded volume. When the armrest link assembly 111 is unfolded, the first telescopic link 311 and the second telescopic link 321 are manually operated to be extended to the appropriate positions. One end of the handrail 112 can slide in the sliding through hole 313 and can also swing in the sliding through hole 313 to realize the hinging of the handrail 112 and the bending section 312.

Further, as shown in fig. 8, a plurality of first sliding pin holes sequentially arranged along the long axis direction are respectively formed on the pipe walls of the two opposite sides of the first sleeve 310; the outer walls of the two opposite sides of the first telescopic rod 311 are respectively provided with a first ball spring positioning bead 314. The number of the first ball spring positioning beads 314 on the first telescopic rod 311 is two. The first ball spring positioning bead 314 can slide into or out of the first sliding pin hole under the action of external force. The first telescopic rod 311 is extruded by the first sliding pin holes by the first ball spring positioning beads 314 under the external pushing and pulling force, the ball heads retract, the first telescopic rod 311 can move in the first sleeve 310 in a telescopic mode, and when the two first ball spring positioning beads 314 move to the positions of the first sliding pin holes again, the ball heads release and slide into the first sliding pin holes, so that the first telescopic rod 311 is positioned after telescopic movement in the first sleeve 310.

A plurality of second sliding pin holes sequentially arranged along the axial direction are respectively formed on the pipe walls of two opposite sides of the second sleeve 320; a plurality of second ball spring positioning beads corresponding to the second sliding pin holes are respectively arranged on the outer walls of the two opposite sides of the second telescopic rod 321. The number of the second ball spring positioning beads on the second telescopic rod 321 is two. The second ball spring positioning bead can slide into or slide out of the second sliding pin hole under the action of external force. The second telescopic rod 321 is extruded by the second sliding pin holes under the external force of pushing and pulling, the ball heads retract, the second telescopic rod 321 can move in the second sleeve 320 in a telescopic mode, and when the two second ball head spring positioning balls move to the positions of one pair of second sliding pin holes again, the ball heads release and slide into the second sliding pin holes, so that the second telescopic rod 321 is positioned after telescopic movement in the second sleeve 320.

In this embodiment, the first telescopic link 311 and the second telescopic link 321 can be simply and conveniently telescopic and positioned, and telescopic positioning is realized through the ball spring positioning beads, so that the size of the structure is smaller.

Further, as shown in fig. 9, the bending section 312 includes: a first bend plate 315 and a second bend plate 316 are symmetrically disposed. The sliding through hole 313 includes: a first sub-via 317 and a second sub-via 318.

One end of the first bending plate 315 is fixedly coupled to the upper end of the first telescopic link 311. The other end of the first bend plate 315 extends toward the handrail 112. The second bending plate 316 and the first bending plate 315 are respectively located at two sides of the first telescopic rod 311 and symmetrically arranged, and one end of the second bending plate 316 is fixedly connected with the upper end of the first telescopic rod 311. The other end of the second bend flap 316 extends toward the handrail 112. The first sub-aperture 317 is located on the first bend plate 315. The second sub-aperture 318 is located in the second bend plate 316. The handrail 112 is provided with a runner 115 on both sides of one end thereof, respectively. Both sides of one end of the handrail 112 are in contact with the first bending flap 315 and the second bending flap 316. The first and second sub-through holes 317, 318 are kidney-shaped holes, and the long axis extends along the long axis of the handrail 112. The two sliding posts 115 are respectively positioned in the first sub through hole 317 and the second sub through hole 318, and are in sliding contact with the first sub through hole 317 and the second sub through hole 318.

In this embodiment, the two sliding posts 115 slide and rotate in the first sub-through hole 317 and the second sub-through hole 318 to drive the handrail 112 to slide and swing on the sliding bending section 312, the bending section 312 and the handrail 112 are matched to realize sliding and hinge matching simultaneously, the structure is simple, and the two sides of the handrail 112 are matched to the first bending plate 315 and the second bending plate 316 in a sliding manner, so that the handrail 112 is stressed in a balanced manner during the sliding process, and the stability is improved. Wherein the major axes of the first and second sub-throughbores 317, 318 are parallel to the handrail 112 when the handrail linkage assembly 111 is deployed.

Further, as shown in fig. 10, taking the following synchronizing lever 140 as an example, the lower synchronizing lever 140 includes: a main rod body 410 and two sliding connection rods 420; the diameter of the slide bar 420 is smaller than the main bar 410. The two ends of the main rod body 410 are fixedly connected with one ends of the two sliding connection rods 420, respectively. The other ends of the two sliding connection rods 420 are respectively hinged with one ends of the two lower driving rods 150 through the two sliding through holes 136, and the two sliding connection rods 420 are in sliding contact with the sliding through holes 136.

Further, as shown in fig. 12, the connection plate 134 includes: a first L-shaped sub-board 510 and a second L-shaped sub-board 520;

the plate surface of the horizontal section of the first L-shaped sub-plate 510 is fixedly connected with the rear longitudinal beam of the lower ladder frame 120, and the edge of the vertical section of the first L-shaped sub-plate 510 opposite to the horizontal section is fixedly connected with the edge of the vertical section of the second L-shaped sub-plate 520 opposite to the horizontal section of the second L-shaped sub-plate 520. The horizontal section of the second L-shaped sub-board 520 extends toward the rear of the lower ladder frame 120.

The horizontal section of the second L-shaped sub-board 520 extends toward the rear of the lower ladder frame 120, and the vertical section of the second L-shaped sub-board 520 is provided with a sliding through hole 136 and a rectangular through hole 521; the rectangular through hole 521 is located above the sliding through hole 136. In the present embodiment, the rectangular through-hole 521 can reduce the weight of the connection plate 134.

Preferably, a reinforcing rod 330 is further provided between the first sleeve 310 and the second sleeve 320. The reinforcing bar 330 is parallel to the handrail 112, and both ends of the reinforcing bar 330 are hinged to the first and second bushings 310 and 320, respectively.

Further, sliding sleeves are arranged on the left longitudinal beam and the right longitudinal beam of the ladder frame. As shown in fig. 12, 13, and 14, the lower slider 170 includes: a first mounting plate 171 and a first slider 172; an upper sliding sleeve 270, comprising: a second mounting plate 271 and a second sled 272.

The first mounting plate 171 is located at the lower end of the lower ladder frame 120, one side of the first mounting plate 171 is fixedly connected with the front rail 121 of the lower ladder frame, the other side of the first mounting plate 171 extends toward the front side of the lower ladder frame 120, and the edge of the other side of the first mounting plate 171 is fixedly connected with the first sliding plate 172. The first sliding plate 172 extends toward the lower step plate 160 of the lower ladder frame 120. Preferably, the lower sliding sleeve 170 may have an L shape, the first mounting plate 171 has a vertical section, and the first sliding plate 172 has a horizontal section. The rear stringers 222 of the upper ladder frame are located between the first mounting plate 171 and the first slide plate 172, and the rear stringers 222 of the upper ladder frame are in sliding contact with the first mounting plate 171 and the first slide plate 172.

The second mounting plate 271 is located at the upper end of the upper ladder frame 220, one side of the second mounting plate 271 is fixedly connected with the rear longitudinal beam 222 of the upper ladder frame, the other side of the second mounting plate 271 extends toward the rear side of the upper ladder frame 220, and the edge of the other side of the second mounting plate 271 is fixedly connected with the second sliding plate 272. The second sliding plate 272 extends toward the upper step plate 260. Preferably, the upper sliding sleeve 270 may have an L shape, the second mounting plate 271 has a vertical section, and the second sliding plate 272 has a horizontal section. The front side member 121 of the lower ladder frame is located between the second mounting plate 271 and the second slide plate 272, and the front side member 121 of the lower ladder frame is in sliding contact with the second mounting plate 271 and the second slide plate 272. In this embodiment, when the telescopic hydraulic ram 280 drives the lower ladder assembly 100 to slide on the rear stringers 222 of the upper ladder frame, the lower sliding sleeve 170 moves slidingly on the rear stringers 222 of the upper ladder frame along with the lower ladder frame 120, so that the front stringers 121 of the lower ladder frame also move slidingly on the upper sliding sleeve 270, to achieve the extension and retraction of the overall length of the lower ladder assembly 100 and the upper ladder assembly 200, thereby adjusting the length of the combined ladder. In this embodiment, the upper sliding sleeve 270 and the lower sliding sleeve 170 have simple structures and are easy to assemble and disassemble, so that the cost is saved and the convenience of installation and maintenance is improved.

Further, a fixing pin hole 261 is formed at a side wall of an end portion of the upper step plate 260 of the upper ladder assembly 200. The first slider 172 is fixedly provided with a protruding connection portion 173. The connection portion 173 is provided with a connection pin hole that mates with the fixing pin hole 261. The fixing pin hole 261 is connected with the connecting pin hole through the positioning pin 174. In this embodiment, two hydraulic telescopic cylinders are respectively fixed on two rear stringers of the upper ladder frame 220, when the telescopic hydraulic cylinder 280 drives the lower ladder assembly 100 to slide on the rear stringers 222 of the upper ladder frame to a required position, the upper step plate 260 and the upper sliding sleeve 270 can be fixedly connected through the positioning pin 174, so that the fixation of the two ladder assemblies after the length telescopic adjustment is further realized, and the stability and reliability of use are enhanced.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Further, one skilled in the art can engage and combine the different embodiments or examples described in this specification.

The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.

Claims (4)

1. A combination ladder for a workover rig, comprising: two ladder assemblies and two armrest assemblies;

The ladder assembly includes: the folding driving mechanism comprises a ladder frame, a folding driving mechanism, a synchronous rod, two driving rods and a plurality of step plates arranged on the ladder frame;

one of the armrest assemblies is arranged on the outer side of the ladder frame of one of the ladder assemblies, and the other armrest assembly is arranged on the front side of the front longitudinal beam of the ladder frame of the other ladder assembly;

the ladder frame of one of the ladder assemblies is positioned at the rear side of the ladder frame of the other ladder assembly;

the synchronous rod is connected with the folding driving mechanism, and two ends of the synchronous rod are respectively hinged with one ends of the two driving rods;

the other ends of the two driving rods are respectively hinged with two side parts of the handrail component;

the folding driving mechanism is arranged on the rear longitudinal beam of the ladder frame and is close to the lower end of the ladder frame, and is used for enabling the synchronous rod to drive the two driving rods to move so as to drive the handrail component to fold or unfold;

two telescopic hydraulic cylinders (280) are arranged on the rear longitudinal beam of the ladder frame of the other ladder assembly;

the telescopic hydraulic oil cylinder (280) has a telescopic direction parallel to the rear longitudinal beam of the ladder frame, the fixed end of the telescopic hydraulic oil cylinder is fixedly connected with the part, close to the lower end, of the rear longitudinal beam of the ladder frame of the other ladder assembly, and the telescopic end of the telescopic hydraulic oil cylinder is fixedly connected with the lower end of the ladder frame of the one ladder assembly;

A lower sliding sleeve (170) is fixedly arranged on the front longitudinal beam of the ladder frame of one ladder assembly, an upper sliding sleeve (270) is fixedly arranged on the rear longitudinal beam of the ladder frame of the other ladder assembly, the front longitudinal beam of the ladder frame of one ladder assembly is in sliding fit with the upper sliding sleeve (270), and the rear longitudinal beam of the ladder frame of the other ladder assembly is in sliding fit with the lower sliding sleeve (170);

the folding driving mechanism includes: a cylinder (131), a support plate (132), a stabilizing plate (133) and two connecting plates (134);

the armrest assembly includes: two armrest link assemblies (111);

the armrest link assembly (111) includes: a handrail (112), a first support rail (113) and a second support rail (114);

the supporting plate (132) is fixedly connected with the rear longitudinal beam of the ladder frame;

the stabilizing plate (133) is fixedly connected with the rear longitudinal beam of the ladder frame;

the fixed end of the air cylinder (131) is fixedly connected with the supporting plate (132) and the stabilizing plate (133) through two L-shaped fixing plates (135) respectively, and the expansion and contraction direction of the air cylinder is parallel to the rear longitudinal beam of the ladder frame;

the connecting plate (134) is fixedly connected with the rear longitudinal beam of the ladder frame and provided with a sliding through hole (136);

The two connection plates (134) are positioned on two side parts of the ladder frame;

the sliding through hole (136) is a waist-shaped hole, and the long axis is parallel to the expansion and contraction direction of the air cylinder (131);

the two ends of the synchronous rod respectively penetrate through the two sliding through holes (136) to be hinged with one ends of the two driving rods, and the two ends of the synchronous rod are in sliding contact with the sliding through holes (136);

the handrail (112) is parallel to the front longitudinal beam, and two ends of the handrail are respectively and movably connected with the upper end of the first support handrail (113) and the upper end of the second support handrail (114);

-the first support rail (113) is parallel to the second support rail (114);

the lower ends of the first support rail (113) and the second support rail (114) of the one of the armrest assemblies are hinged with the upper end and the lower end of the outer side portion of the ladder frame of the one of the ladder assemblies, respectively;

the lower ends of a first support rail (113) and a second support rail (114) of the other handrail assembly are respectively hinged with the upper end and the lower end of the front side part of the front longitudinal beam of the ladder frame of the other ladder assembly;

the other ends of the two driving rods are respectively hinged with the rod parts of the second support railings (114) of each handrail connecting rod assembly (111);

The first support rail (113) comprises: a first sleeve (310), a first telescopic rod (311) and a bending section (312); the second support rail (114) comprising: a second sleeve (320) and a second telescoping rod (321);

the lower end of the first sleeve (310) is hinged with the outer side part of the ladder frame near the upper end;

the first telescopic rod (311) penetrates into the first sleeve (310) from the upper end of the first sleeve (310), is in sliding connection with the first sleeve (310), and is fixedly connected with one end of the bending section (312);

the other end of the bending section (312) extends towards the handrail (112) and is provided with a sliding through hole (313);

the sliding through hole (313) is a waist-shaped hole, and a long shaft extends along the long shaft direction of the handrail (112);

one end of the handrail (112) is movably connected with the sliding through hole (313), and the other end of the handrail is hinged with the upper end of the second telescopic rod (321);

the second telescopic rod (321) penetrates into the second sleeve (320) from the upper end of the second sleeve (320) and is in sliding connection with the second sleeve (320);

the lower end of the second sleeve (320) is hinged with the outer side part of the ladder frame near the lower end;

the lower ends of the first sleeve (310) and the second sleeve (320) of one of the armrest assemblies are respectively hinged with the upper end and the lower end of the outer side part of the ladder frame of one of the ladder assemblies;

The lower ends of the first sleeve (310) and the second sleeve (320) of the other handrail component are respectively hinged with the upper end and the lower end of the front side part of the front longitudinal beam of the ladder frame of the other ladder assembly;

the other ends of the two driving rods are respectively hinged with the rod parts of the first sleeve (310) of each armrest connecting rod assembly (111);

wherein, when the armrest link assembly (111) is deployed, a long axis of the sliding through-hole (313) is parallel to the armrest rail (112);

the synchronous rod comprises a main rod body (410) and two sliding connection rods (420); the diameter of the sliding connection rod (420) is smaller than that of the main rod body (410);

the two ends of the main rod body (410) are fixedly connected with one ends of two sliding connection rods (420) respectively;

the other ends of the two sliding connection rods (420) respectively pass through the two sliding through holes (136) to be hinged with one ends of the two driving rods and are in sliding contact with the sliding through holes (136);

the two ladder assemblies include a lower ladder assembly (100) and an upper ladder assembly (200);

the ladder frame of the lower ladder assembly (100) is a lower ladder frame (120), and the ladder frame of the upper ladder assembly (200) is an upper ladder frame (220);

the lower ladder frame (120) is positioned at a rear side of the upper ladder frame (220);

The lower sliding sleeve (170) is fixedly arranged on the front longitudinal beam (121) of the lower ladder frame, the upper sliding sleeve (270) is fixedly arranged on the rear longitudinal beam (222) of the upper ladder frame, the front longitudinal beam (121) of the lower ladder frame is in sliding fit with the upper sliding sleeve (270), and the rear longitudinal beam (222) of the upper ladder frame is in sliding fit with the lower sliding sleeve (170);

the bending section (312) comprises: a first bending plate (315) and a second bending plate (316) which are symmetrically arranged; the sliding through hole (313) includes: a first sub-via (317) and a second sub-via (318);

the first bending plate (315) is fixedly connected with the upper end of the first telescopic rod (311) at one end, and the other end extends towards the handrail (112);

the second bending plate (316) and the first bending plate (315) are respectively and symmetrically arranged at two sides of the first telescopic rod (311), one end of the second bending plate is fixedly connected with the upper end of the first telescopic rod (311), and the other end of the second bending plate extends towards the handrail (112);

-said first sub-through hole (317) being located on said first bending plate (315);

-said second sub-aperture (318) being located on said second bending plate (316);

both sides of one end of the handrail (112) are respectively provided with a sliding column (115);

The two sliding posts (115) are respectively positioned in the first sub through hole (317) and the second sub through hole (318) and are in sliding contact with the first sub through hole (317) and the second sub through hole (318).

2. A combined ladder for a workover rig according to claim 1, c h a r a c t e r i z e d in that between the first casing (310) and the second casing (320) there is also provided a reinforcement bar (330);

the reinforcing rod (330) is parallel to the handrail (112), and two ends of the reinforcing rod are respectively hinged with the first sleeve (310) and the second sleeve (320).

3. The combined ladder of the workover rig according to claim 1, wherein a plurality of first sliding pin holes sequentially arranged along the long axis direction are respectively formed on the pipe walls of two opposite sides of the first sleeve (310); the outer walls of the two opposite sides of the first telescopic rod (311) are respectively provided with a first ball spring positioning bead (314);

the first ball spring positioning bead (314) can slide into or slide out of the first sliding pin hole under the action of external force;

a plurality of second sliding pin holes which are sequentially arranged along the long axis direction are respectively formed on the pipe walls of two opposite sides of the second sleeve (320); second ball spring positioning beads are respectively arranged on the outer walls of the two opposite sides of the second telescopic rod (321);

The second ball spring positioning bead can slide into or slide out of the second sliding pin hole under the action of external force.

4. A combination ladder for a workover rig according to claim 1, wherein the web (134) comprises: a first L-shaped daughter board (510) and a second L-shaped daughter board (520);

the first L-shaped sub board (510) is fixedly connected with the rear longitudinal beam of the ladder frame, and the vertical section is fixedly connected with the vertical section of the second L-shaped sub board (520);

the second L-shaped daughter board (520) extends towards the rear of the ladder frame, and the sliding through hole (136) and the rectangular through hole (521) are formed in the vertical section;

the rectangular through hole (521) is positioned at the sliding through

Above the aperture (136).