CN115450552A - Combined ladder of workover rig - Google Patents

Abstract

The invention discloses a combined ladder of a workover rig, which comprises: two ladder assemblies and two handrail components; one of the rail members is disposed on an outboard side of the ladder frame of one of the ladder assemblies and the other rail member is disposed on a forward side of a front rail of the ladder frame of the other ladder assembly; two telescopic hydraulic oil 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 one of the ladder assemblies 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. According to the foldable handrail assembly, the handrail assembly can be folded or unfolded, the handrail assembly can be folded in the transportation and storage processes, the occupied space is small, and the transportation and storage convenience is improved. Simultaneously, can adjust the height of combination ladder, be applicable to the operating mode of co-altitude not and use, it 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 kind of specialized fossil oil exploration equipment used for well drilling and workover, mainly used for the lifting and lowering of drilling rod, oil line, sucker rod, the large and small workover works such as pit shaft restoration, windowing, etc..

At present, workover rig ladders are fixed, can only highly use at a working condition, and the ladder height can't be adjusted, can not satisfy the installation operation requirement of height-adjustable's workover platform, and handrail railing (112) are fixed mounting on the railing seat, and when the ladder was maintained in the installation, occupation space was great in transportation and the storage process, and transportation and storage were very inconvenient.

Disclosure of Invention

In order to solve the above problems in the prior art, the present invention provides a combination ladder of a workover rig. The technical problem to be solved by the invention is realized by the following technical scheme:

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

the ladder assembly comprising: the folding ladder 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 rail members is disposed on an outboard side of the ladder frame of one of the ladder assemblies and the other rail member is disposed on a forward side of a front rail of the ladder frame of the other ladder assembly;

the ladder frame of one of the ladder assemblies is positioned at a position rearward 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 the two side parts of the handrail component;

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

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

the telescopic direction of the telescopic hydraulic oil cylinder is 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;

one of them fixed lower sliding sleeve that is provided with on the front longitudinal beam of the ladder frame of ladder assembly, fixed upper sliding sleeve that is provided with on the back longitudinal beam of the ladder frame of another ladder assembly, one of them the front longitudinal beam of the ladder frame of ladder assembly with go up sliding sleeve sliding fit, the back longitudinal beam of the ladder frame of another ladder assembly with lower sliding sleeve sliding fit.

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

the armrest assembly, comprising: two handrail connecting rod assemblies;

the armrest linkage assembly, comprising: the handrail, the first support rail and the 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 respectively and fixedly connected with the supporting plate and the stabilizing plate 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 is 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 axis of the sliding through hole is parallel to the telescopic direction of the cylinder;

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 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 movably connected with the upper end of the first supporting handrail and the upper end of the second supporting handrail respectively;

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 assemblies;

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 part of the second supporting handrail of each handrail connecting rod component.

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 a 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 in sliding connection with the second sleeve;

the lower end of the second sleeve is hinged with the position, close to 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 assemblies;

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 handrail connecting rod component;

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

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

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

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

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

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

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

In one embodiment of the invention, the synchronous rod comprises a main rod body and two sliding connecting rods; the diameter of the sliding connection rod is smaller than that of the main rod body;

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

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

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

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

the horizontal section of the second L-shaped sub-plate extends towards the rear of the ladder rack, and the vertical section of the second L-shaped sub-plate is provided with the sliding through hole and the rectangular through hole;

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

In one embodiment of the invention, the two ladder assemblies comprise 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 front longitudinal beam of the lower ladder frame is fixedly provided with the lower sliding sleeve, the rear longitudinal beam of the upper ladder frame is fixedly provided with the upper sliding sleeve, 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 slide 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 symmetrically arranged on two sides of the first telescopic rod respectively, 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 hole is positioned on the first bending plate;

the second sub through hole is 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:

the combined ladder structure is formed by the two ladder assemblies and the corresponding handrail components, the handrail components can be folded or unfolded under the driving of the folding driving mechanism, and the handrail components can be folded in the transportation and storage processes when the ladder is installed and maintained, so that the occupied space is small, and the convenience in transportation and storage is improved. Simultaneously, can drive a ladder assembly through flexible hydraulic cylinder and slide on another ladder assembly to make the combination ladder can extend or withdraw, and then can adjust the height of combination ladder, satisfy height-adjustable's well workover platform's installation operation requirement, be applicable to the operating mode use of co-altitude not, it 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 side view of a well servicing rig in the extended deployed configuration of a combination ladder according to an embodiment of the present invention;

FIG. 2 is a side view of the rear of a workover rig incorporating the combination ladder of the present invention in an extended deployed condition;

FIG. 3 is an enlarged partial schematic view of a folding drive mechanism of a workover rig combination ladder in an extended and unfolded state according to an embodiment of the present invention;

FIG. 4 is a schematic view of a portion of an enlarged structure of a folding driving mechanism at a rear side view of an extended and unfolded state of a combined ladder 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 the handle link assembly of the combination ladder of the workover rig according to the embodiment of the present invention;

FIG. 6 is a structural schematic illustration of a lower ladder assembly in a rear side view of an extended deployed condition of a combination ladder of a workover rig in accordance with an embodiment of the present invention;

fig. 7 is a schematic structural view of a first support rail provided by an embodiment of the present invention;

fig. 8 is a schematic view of the configuration of the first support rail and the handrail in cooperation according to an embodiment of the present invention;

fig. 9 is a schematic structural view of the engagement between the bending section and the handrail in a folded state of the handrail connecting rod assembly according to the embodiment of the present invention;

FIG. 10 is a schematic diagram of the structure of the cylinder and the lower synchronizing bar provided by the embodiment of the present invention;

FIG. 11 is a side elevational view of the assembled ladder of a workover rig shown in the extended forward position in accordance with an embodiment of the present invention;

FIG. 12 is an enlarged partial schematic view of the workover rig at the web of the front side view of the extended and deployed state of the assembled ladder of the present invention;

FIG. 13 is an enlarged partial structural view of the lower and upper slips of a workover rig according to an embodiment of the present invention, as viewed from the rear side of the extended and deployed state of the assembled ladder;

fig. 14 is a side structural view of a well servicing rig in a collapsed folded state of a built-up ladder according to an embodiment of the present invention.

Description of reference numerals:

100-a lower ladder assembly; 110-a lower armrest assembly; 111-handrail linkage assembly; 112-a handrail; 113-a first support rail; 114-a second support rail; 115-sliding columns; 120-going down the ladder; 121-front longitudinal beam of lower ladder frame; 122-rear stringer of lower ladder frame; 130-a lower fold drive mechanism; 131-a cylinder; 132-a support plate; 133-a stabilizer plate; 134-a connecting plate; 135-L shaped fixing plate; 136-a sliding through hole; 140-lower synchronization bar; 150-lower driving lever; 160-lower step plate; 170-lower sliding sleeve; 171-a first mounting plate; 172-a first sled; 173-a connecting part; 174-locating pins; 200-an upper ladder assembly; 210-an upper armrest assembly; 220-going up the ladder; 221-front longitudinal beam of upper ladder frame; 222-rear stringer of going-up ladder; 230-an upper folding drive mechanism; 240-upper synchronization bar; 250-upper driving rod; 260-upper step plate; 261-fixing pin hole; 270-upper sliding sleeve; 271-a second mounting plate; 272-a second slide plate; 280-a telescopic hydraulic oil cylinder; 310-a first sleeve; 311-a first telescopic rod; 312-bending section; 313-sliding through holes; 314-a first ball spring locator bead; 315-a first bending plate; 316-a second bending plate; 317-a first sub-via; 318-second sub-via; 320-a second sleeve; 321-a second telescopic rod; 330-a stiffener; 410-a main rod body; 420-sliding connecting rod; 510-a first L-shaped daughter board; 520-a second L-shaped daughter board; 521-rectangular through hole.

Detailed Description

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

Example one

As shown in fig. 1, 2 and 14, a combination ladder of a workover rig includes: two ladder assemblies and two handrail components; a ladder assembly comprising: ladder frame, folding actuating mechanism, synchronizing bar, two initiative poles and a plurality of step boards of setting on ladder frame. A plurality of step boards set up on the ladder frame from top to bottom in proper order.

Specifically, the two ladder assemblies are one lower ladder assembly 100 and the other upper ladder assembly 200, and the two rail members are a lower rail member 110 and an upper rail member 210, respectively. 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 step 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 step frame 120.

One of the rail members is disposed on an outboard side of the ladder frame of one of the ladder assemblies and the other rail member is disposed on a forward side of a front rail of the ladder frame of the other ladder assembly. Specifically, the lower rail assembly 110 is disposed on an outer side of the lower ladder frame 120 of the lower ladder assembly 100 and the upper rail assembly 210 is disposed on a 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 each other in the connecting position with the two ladder frames.

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

As shown in the figure, the following active lever 150, lower synchronizing lever 140 and lower folding driving mechanism 130 are taken as examples to be described in detail: the lower synchronizing bar 140 is connected to the lower folding driving mechanism 130, and both ends of the lower synchronizing bar 140 are respectively hinged to one ends of the two lower driving bars 150. The other end of one of the lower driving levers 150 is hinged to one side portion of the lower handle assembly 110. The other end of the other lower driving link 150 is hinged to the other side of the lower handle 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 configured to enable the lower synchronizing bar 140 to drive the two lower driving bars 150 to move so as to drive the lower handrail assembly 110 to fold or unfold. The lower folding driving mechanism 130 is used to make the lower synchronizing bar 140 drive the lower driving bar 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 bar 240 and the upper driving bar 250 are not described in detail.

In this embodiment, under the drive of folding actuating mechanism, the synchronizing bar can drive two initiative poles motion in order to drive handrail components folding or expansion simultaneously. Specifically, two handrail connecting rod assemblies 111 are respectively arranged at two side portions of the handrail assembly, the two handrail connecting rod assemblies 111 are respectively positioned on ladder frames at two sides of the step plate (left side and right side of the step plate), two driving rods are positioned at two sides of the step plate, and the other end of each driving rod is hinged to the handrail connecting rod assembly 111 at the corresponding side. For example, the lower folding driving mechanism 130 is configured such that the lower synchronization 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 oil cylinders 280 are arranged on the rear longitudinal beam of the ladder frame of the other ladder assembly, the telescopic directions of the telescopic hydraulic oil cylinders 280 are parallel to the rear longitudinal beam of the ladder frame, the fixed ends of the telescopic hydraulic oil cylinders 280 are 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 ends of the telescopic hydraulic oil cylinders 280 are fixedly connected with the lower end of the ladder frame of the one ladder assembly. The front longitudinal beam and the rear longitudinal beam of the ladder frame are parallel. Specifically, two telescopic hydraulic rams 280 are provided on the rear stringers 222 of the ladder going upstairs. The telescopic direction of the telescopic hydraulic oil cylinder 280 is parallel to the rear longitudinal beam 222 of the upper ladder frame, the fixed end of the telescopic hydraulic oil cylinder 280 is fixedly connected with the part of the rear longitudinal beam 222 of the upper ladder frame, which is close to the lower end, and the telescopic end of the telescopic hydraulic oil 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 rack is fixedly provided with a lower sliding sleeve 170, the rear longitudinal beam 222 of the upper ladder rack is fixedly provided with an upper sliding sleeve 270, the front longitudinal beam 121 of the lower ladder rack is in sliding fit with the upper sliding sleeve 270, and the rear longitudinal beam 222 of the upper ladder rack is in sliding fit with the lower sliding sleeve 170. The lower handle assembly 110 is disposed on an outer side of the lower ladder frame 120, and the upper handle assembly 210 is disposed on a front side of a front rail 221 of the upper ladder frame. When the telescopic hydraulic rams 280 are used to drive the lower ladder assembly 100 to slide along the rear stringers 222 of the upper ladder frame, the upper rail members 210 are positioned between the lower rail members 110, and the lower rail members 110 move within the space between the outer sides of the upper rail members 210 without interfering with the sliding movement of the lower ladder frame assembly along the rear stringers 222 of the upper ladder frame.

In this embodiment, the folding driving mechanism is used to drive the synchronizing rod to drive the driving rod to move so as to drive the handle assembly to fold or unfold, 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 extend or shorten the total length of the two ladder assemblies, and the height of the combined ladder can be adjusted. Specifically, when the telescopic hydraulic rams 280 drive the lower ladder assembly 100 to slide on the rear longitudinal beam 222 of the upper ladder frame, the lower sliding sleeve 170 slides along the rear longitudinal beam 222 of the upper ladder frame along with the lower ladder frame 120, so that the front longitudinal beam 121 of the lower ladder frame also slides in the upper sliding sleeve 270, thereby extending and retracting the total length of the lower ladder assembly 100 and the upper ladder assembly 200, and adjusting the length of the combined ladder. In the embodiment, the two ladder assemblies and the corresponding handrail components form a combined ladder structure, the handrail components can be folded or unfolded under the driving of the folding driving mechanism, and the handrail components can be folded in the transportation and storage processes when the ladder is installed and maintained, so that the occupied space is small, and the transportation and storage convenience is improved. Simultaneously, can drive one (lower floor) ladder assembly through flexible hydraulic cylinder 280 and slide on another (upper strata) ladder assembly to make the combination ladder can extend or withdraw, and then can adjust the height of combination ladder, satisfy height-adjustable's well workover platform's installation operation requirement, be applicable to the operating mode use of not co-altitude, it is convenient to use.

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

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 connecting plates 134.

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

Some components in this embodiment are described in detail in the following ladder assembly 100 as an example, and the same structure of the upper ladder assembly 200 is not described again.

Handrail link assembly 111 includes: a hand rail 112, a first support rail 113, and a second support rail 114.

The support plate 132 is fixedly connected to the rear side member of the lower ladder frame 120. The stabilizing plate 133 is fixedly connected to the rear side member 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, and the expansion direction of the cylinder 131 is parallel to the rear longitudinal beam 121 of the down ladder. In this embodiment, the two L-shaped fixing plates 135 are respectively and fixedly connected to the supporting plate 132 and the stabilizing plate 133, and the fixing end of the cylinder 131 is fixedly connected to the two L-shaped fixing plates 135.

The connecting 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 connecting plate 134. The two connecting plates 134 are respectively located on two side portions of the ladder frame, and the two connecting plates 134 are respectively fixedly connected with the two rear longitudinal beams. The slide through hole 136 is a kidney-shaped hole, and the long axis of the slide through hole 136 is parallel to the extending and contracting direction of the cylinder 131. Two ends of the synchronizing rod respectively penetrate through the two sliding through holes 136 to be 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 handrail 112 is parallel to the front longitudinal beam 121 of the down ladder, and two ends of the handrail 112 are movably connected with the upper end of the first support handrail 113 and the upper end of the second support handrail 114 respectively. The first support rail 113 is parallel to the second support rail 114. When the handrail connecting rod assembly 111 is unfolded, the handrail 112, the first and second support rails 113 and 114 and the front longitudinal beam 121 of the lower ladder rack form a parallelogram structure.

The lower ends of the first 113 and second 114 support rails of the other hand rail assembly are hingedly connected to the upper and lower ends, respectively, of the front side of the front rail of the ladder frame 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 of the front side rail 221 of the upper ladder frame, respectively.

The other ends of the two driving links are respectively hinged to the rod portion of the second support rail 114 of each handrail connecting link assembly 111. Specifically, the other end of each lower driving link 150 is hinged to the rod portion of the second support rail 114 of each handrail 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, accordingly, the cylinder 131 extends 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 handrail 114, an angle between the other end of the lower driving rod 150 and the second supporting handrail 114 is reduced, the second supporting handrail 114 drives the handrail 112 and the first supporting handrail 113 to move, and the handrail connecting rod assembly 111 moves upward and unfolds as a whole. Conversely, the cylinder 131 contracts to drive the lower synchronous rod 140 to slide backwards, the lower synchronous rod 140 pulls the lower driving rod 150 to move, the lower driving rod 150 pulls the second supporting handrail 114, the angle between the other end of the lower driving rod 150 and the second supporting handrail 114 is increased, and the handrail connecting rod assembly 111 moves downwards integrally to be folded together.

In this embodiment, can realize the automation of two handrail subassemblies through cylinder 131 drive connecting rod structure and expand and fold, when the ladder was maintained in the installation, can fold handrail subassembly in transportation and the storage process, occupation space is less, has improved the convenience of transportation and storage. Meanwhile, the first support railing 113 and the second support railing 114 of the handrail assembly are hinged to the ladder frame, and can be detached from the ladder frame during installation and maintenance, so that the installation and maintenance convenience is improved, and the transportation and storage convenience 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 telescopic rod 311 and a bending section 312; a second support rail 114 comprising: a second cannula 320 and a 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 rail 121 of the lower 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, the first telescopic rod 311 is slidably connected 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 on the bending section 312. The slide through hole 313 is a kidney-shaped hole, and a long axis of the slide through hole 313 extends along a 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 connected with the second sleeve 320 in a sliding manner. The lower end of the second thimble 320 is hinged to the outer side of the ladder frame near the lower end (the lower end of the second thimble 320 is hinged to the outer side of the rear longitudinal beam 121 of the lower ladder frame near the lower end).

It should be noted that the lower ends of the first and second sleeves 310, 320 of the other handrail assembly are hingedly connected to the upper and lower ends, respectively, of the front side of the front rail of the ladder frame of the other ladder assembly. Specifically, the lower ends of the first and second bushings 310 and 320 of the upper handle assembly 210 are respectively hinged to the upper end of the front side member 221 of the upper ladder frame and the lower end of the front side member 221 of the upper ladder frame. The other ends of the two lower driving links 150 are respectively hinged to the rod portion of the first bushing 310 of each handrail connecting rod assembly 111.

When the handrail connecting rod assembly 111 is unfolded, the long axis of the sliding through hole 313 is parallel to the handrail 112.

In this embodiment, the first telescopic rod 311 can be extended and retracted in the first sleeve 310 under the action of an external force, and the second telescopic rod 321 can be extended and retracted in the second sleeve 320 under the action of an external force, so that the folded handrail connecting rod assembly 111 has a smaller volume. Specifically, when the handrail connecting rod assembly 111 is folded, the first telescopic rod 311 and the second telescopic rod 321 are manually operated to retract into the first sleeve 310 and the second sleeve 320 by a certain length, and the folded length of the handrail connecting rod assembly 111 is relatively shorter, so that the folded volume is reduced. After the handrail connecting rod assembly 111 is unfolded, the first telescopic rod 311 and the second telescopic rod 321 are manually operated to extend to proper 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 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 ball 314. The number of the first ball spring positioning balls 314 on the first telescopic rod 311 is two. The first ball spring retaining bead 314 may slide into or out of the first slide pin hole under an external force. The first ball spring positioning balls 314 of the first telescopic rod 311 are extruded by the first sliding pin holes under the external force of pushing and pulling, 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 balls 314 move to the positions of the pair of 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 in the first sleeve 310 after the telescopic movement.

The pipe walls of two opposite sides of the second sleeve 320 are respectively provided with a plurality of second sliding pin holes which are sequentially arranged along the axial direction; 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 expansion link 321 is two. The second ball spring positioning ball can slide into or out of the second sliding pin hole under the action of external force. The second ball spring positioning beads of the second expansion link 321 are extruded by the second sliding pin holes under the external force of pushing and pulling, the ball head retracts, the second expansion link 321 can move in the second sleeve 320 in a telescopic mode, and when the two second ball spring positioning beads move to the position of one pair of the second sliding pin holes again, the ball head is released to slide into the second sliding pin holes, so that the second expansion link 321 is positioned in the second sleeve 320 after the telescopic movement.

In this embodiment, first telescopic link 311 and second telescopic link 321 can realize simply stretching out and drawing back conveniently and fix a position, realize flexible location through bulb spring location ball, and the volume of structure is less.

Further, as shown in fig. 9, the bending section 312 includes: a first bending plate 315 and a second bending 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 connected to the upper end of the first telescopic rod 311. The other end of the first bent plate 315 extends toward the balustrade 112. The second bending plate 316 and the first bending plate 315 are symmetrically disposed at two sides of the first telescopic rod 311, and one end of the second bending plate 316 is fixedly connected to the upper end of the first telescopic rod 311. The other end of the second bent plate 316 extends toward the balustrade 112. The first sub-via 317 is located on the first bending plate 315. The second sub through hole 318 is formed in the second bending plate 316. Sliding posts 115 are respectively disposed on both sides of one end of the handrail 112. Both sides of one end of the handrail 112 are in contact with the first bending plate 315 and the second bending plate 316. The first sub through hole 317 and the second sub through hole 318 are waist-shaped holes, and the long axes of the waist-shaped holes extend along the long axis direction of the handrail 112. The two sliding pillars 115 are respectively located 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, and the matching between the bending section 312 and the handrail 112 realizes sliding and hinged matching at the same time, so that the structure is simple, and the two sides of the handrail 112 are in sliding matching with the first bending plate 315 and the second bending plate 316, so that the handrail 112 is stressed in a balanced manner during the sliding process, and the stability is improved. When the handrail connecting rod assembly 111 is unfolded, the long axes of the first sub through hole 317 and the second sub through hole 318 are parallel to the handrail 112.

Further, as shown in fig. 10, the following synchronization lever 140 is taken as an example, and the lower synchronization lever 140 includes: a main rod body 410 and two sliding connection rods 420; the diameter of the sliding rod 420 is smaller than that of the main rod body 410. Two ends of the main rod body 410 are fixedly connected to one ends of the two sliding connection rods 420. The other ends of the two sliding connection rods 420 respectively penetrate through the two sliding through holes 136 to be hinged with one ends of the two lower driving rods 150, 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 surface of the horizontal section of the first L-shaped sub-board 510 is fixedly connected with the rear longitudinal beam of the lower ladder 120, and the edge of the vertical section of the first L-shaped sub-board 510, which is opposite to the horizontal section, is fixedly connected with the edge of the vertical section of the second L-shaped sub-board 520, which is opposite to the horizontal section of the second L-shaped sub-board 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-plate 520 extends towards the rear of the lower ladder rack 120, and the vertical section of the second L-shaped sub-plate 520 is provided with a sliding through hole 136 and a rectangular through hole 521; the rectangular through-hole 521 is located above the slide through-hole 136. In this embodiment, the rectangular through-hole 521 can reduce the weight of the connection plate 134.

Preferably, a reinforcing rod 330 is further disposed between the first sleeve 310 and the second sleeve 320. The reinforcing bar 330 is parallel to the balustrade 112, and both ends of the reinforcing bar 330 are hinged to the first and second sleeves 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 slip ring 170 includes: a first mounting plate 171 and a first slide plate 172; an upper sliding sleeve 270, comprising: a second mounting plate 271 and a second slide plate 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 longitudinal beam 121 of the lower ladder frame, the other side of the first mounting plate 171 extends towards 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 step frame 120. Preferably, the lower slip 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 side member 222 of the upper ladder frame is positioned between the first mounting plate 171 and the first sliding plate 172, and the rear side member 222 of the upper ladder frame is in sliding contact with the first mounting plate 171 and the first sliding plate 172.

The second mounting plate 271 is located the upper end of going up the ladder 220, and one side of second mounting plate 271 and the rear longitudinal beam 222 fixed connection of going up the ladder, and the other side of second mounting plate 271 extends towards the rear side of going up ladder 220, and the other side border and the second slide 272 fixed connection of second mounting plate 271. 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 going-down frame is positioned between the second mounting plate 271 and the second sliding plate 272, and the front side member 121 of the going-down frame is in sliding contact with the second mounting plate 271 and the second sliding plate 272. In this embodiment, when the telescopic hydraulic rams 280 drive the lower ladder assembly 100 to slide along the rear longitudinal beam 222 of the upper ladder frame, the lower sliding sleeve 170 slides along the rear longitudinal beam 222 of the upper ladder frame along with the lower ladder frame 120, so that the front longitudinal beam 121 of the lower ladder frame also slides along the upper sliding sleeve 270, thereby extending and retracting the total length of the lower ladder assembly 100 and the upper ladder assembly 200, and adjusting the length of the combined ladder. In this embodiment, the upper sliding sleeve 270 and the lower sliding sleeve 170 are simple in structure and easy to mount and dismount, so that the cost is saved, and the convenience of mounting and maintenance is improved.

Further, a fixing pin hole 261 is formed in a side wall of an end portion of the upper step plate 260 of the upper step assembly 200. The first sliding plate 172 is fixedly provided with a protruding connection portion 173. The connecting portion 173 is provided with a connecting pin hole matching with the fixing pin hole 261. The fixing pin hole 261 is connected with the connecting pin hole by the positioning pin 174. In this embodiment, two hydraulic telescopic cylinders are respectively fixed on two rear longitudinal beams of the upper ladder frame 220, and when the telescopic hydraulic cylinder 280 drives the lower ladder assembly 100 to slide on the rear longitudinal beam 222 of the upper ladder frame and 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 fixing after the length telescopic adjustment of the two ladder assemblies is further realized, and the stability and the reliability of the use are enhanced.

In the description of the present invention, it is to 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", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

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

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation that the first and second features are not in direct contact, but are in contact via another feature between them. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the specification, reference to the description of "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like 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 invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer 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. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims (9)

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

the ladder assembly comprising: the folding ladder 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 handrail components is arranged on the outer side part of the ladder frame of one of the ladder assemblies, and the other handrail component is arranged on the front side part 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 a position rearward 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 end of each of the two driving rods;

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

the folding driving mechanism is arranged on the rear longitudinal beam of the ladder frame, 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 oil cylinders (280) are arranged on the rear longitudinal beam of the ladder frame of the other ladder assembly;

the telescopic direction of the telescopic hydraulic oil cylinder (280) is 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;

one of them fixed lower sliding sleeve (170) that is provided with on the front longitudinal beam of the ladder frame of ladder assembly, fixed upper sliding sleeve (270) that is provided with on the back longitudinal beam of the ladder frame of another ladder assembly, one of them the front longitudinal beam of the ladder frame of ladder assembly with upper sliding sleeve (270) sliding fit, the back longitudinal beam of the ladder frame of another ladder assembly with lower sliding sleeve (170) sliding fit.

2. A combination ladder of a workover rig according to claim 1, wherein the folding drive mechanism comprises: the device comprises a cylinder (131), a support plate (132), a stabilizing plate (133) and two connecting plates (134);

the armrest assembly, comprising: two armrest link assemblies (111);

the armrest linkage assembly (111) comprising: a hand rail (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 respectively and fixedly connected with the supporting plate (132) and the stabilizing plate (133) through two L-shaped fixing plates (135), and the telescopic 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 is provided with a sliding through hole (136);

the two connecting 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 of the sliding through hole is parallel to the telescopic direction of the air cylinder (131);

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 movably connected with the upper end of the first supporting handrail (113) and the upper end of the second supporting handrail (114) respectively;

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 rail assemblies are hinged to the upper end and the lower end of the outer side of the ladder frame of the one of the ladder assemblies, respectively;

the lower ends of the first support railing (113) and the second support railing (114) 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 second supporting railing (114) of each handrail connecting rod component (111).

3. A combination ladder of a workover rig according to claim 2, wherein the first support rail (113) comprises: the device 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 telescopic rod (321);

the lower end of the first sleeve (310) is hinged with the position, close to the upper end, of the outer side part of the ladder frame;

the first telescopic rod (311) penetrates into the first sleeve (310) from the upper end of the first sleeve (310) and is in sliding connection with the first sleeve (310), and the upper end of the first telescopic rod 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 the long axis of the sliding through hole 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 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 connected with the second sleeve (320) in a sliding manner;

the lower end of the second sleeve (320) is hinged with the position, close to the lower end, of the outer side part of the ladder frame;

the lower ends of the first sleeve (310) and the second sleeve (320) of the one of the rail assemblies are respectively hinged with the upper end and the lower end of the outer side part of the ladder frame of the 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 part of the first sleeve (310) of each handrail connecting rod component (111);

when the handrail connecting rod assembly (111) is unfolded, the long axis of the sliding through hole (313) is parallel to the handrail (112).

4. A ladder as claimed in claim 3, characterised in that a reinforcing bar (330) is also provided between the first casing (310) and the second casing (320);

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).

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

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

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

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

6. A combination ladder of a workover rig according to claim 1, wherein the synchronizing bar comprises a main bar body (410) and two skid bars (420); the diameter of the sliding rod (420) is smaller than that of the main rod body (410);

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

and the other ends of the two sliding connecting rods (420) respectively penetrate 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).

7. A combination ladder of a workover rig according to claim 2, wherein the connection plate (134) comprises: a first L-shaped sub-plate (510) and a second L-shaped sub-plate (520);

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

the horizontal section of the second L-shaped sub-plate (520) extends towards the rear of the ladder frame, and the vertical section of the second L-shaped sub-plate is provided with the sliding through hole (136) and a rectangular through hole (521);

the rectangular through hole (521) is located above the sliding through hole (136).

8. A workover rig combination ladder as claimed in claim 3, wherein the two ladder assemblies comprise a lower ladder assembly (100) and an upper ladder assembly (200);

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

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

the front longitudinal beam (121) of the lower ladder rack is fixedly provided with the lower sliding sleeve (170), the rear longitudinal beam (222) of the upper ladder rack is fixedly provided with the upper sliding sleeve (270), the front longitudinal beam (121) of the lower ladder rack is in sliding fit with the upper sliding sleeve (270), and the rear longitudinal beam (222) of the upper ladder rack is in sliding fit with the lower sliding sleeve (170).

9. A ladder as claimed in claim 8, characterised in that said bending section (312) comprises: a first bending plate (315) and a second bending plate (316) which are symmetrically arranged; the sliding through hole (313) comprises: a first sub-via (317) and a second sub-via (318);

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

the second bending plate (316) and the first bending plate (315) are symmetrically arranged on two sides of the first telescopic rod (311) respectively, 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);

the first sub through hole (317) is positioned on the first bending plate (315);

the second sub through hole (318) is positioned on the second bending plate (316);

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

the two sliding columns (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).

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