JP2000064345A - Operating device for construction equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operating device for a construction equipment, in which a bolding functional valve is installed compactly to an offset cylinder. SOLUTION: A holding functional valve capable of holding the oiltight state of a head-side oil chamber and a rod-side oil chamber for an offset cylinder 13a is fixed and mounted so as not to be approximately projected in the vertical direction from an offset boom 6a to the offset cylinder 13a. In the holding functional valve, a head-side holding functional valve and a rod-side holding functional valve are constituted in separate body respectively, an elastic piping is piped as an oil passage communicating a direction changeover valve for an offset and the holding functional valve, and the holding functional valve is fixed by a band member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working device mainly mounted on a construction machine such as a hydraulic excavator, for example, a working device for side excavation.

[0002]

2. Description of the Related Art FIG. 10 is a side view of a hydraulic excavator 1 which has been used more often than before. In the figure, 2 is an upper revolving structure of the hydraulic excavator 1, 3 is a lower traveling structure, 4 is a side digging attachment (hereinafter referred to as a side digging work device) equipped on the front part of the upper revolving structure 2. Is a rear boom (hereinafter referred to as a lower boom) of the side excavation work device 4, 6 is a front boom (hereinafter referred to as an offset boom), 7 is an upper boom, 8 is an arm, 9 is a bucket, 10 is a boom cylinder, and 11 is an arm cylinder. 1
2 is a bucket cylinder and 13 is an offset cylinder.

FIG. 11 is a side view of a main portion of a side edge excavating work device 4'described in Japanese Utility Model Laid-Open No. 6-71988. In the figure, the side excavation work device 4 shown in FIG.
The same reference numerals are given to those using the same constituent elements as. 5'is a lower boom, 25 is a bracket plate of the pipe mounting device 24, 26a and 26b are hydraulic hoses (elastic pipes) of the pipes leading to the head side oil chamber of the arm cylinder 11, and 27a and 27b are bucket cylinders 12 respectively.
Of the pipes communicating with the head side oil chamber, and 28a, 28b are hydraulic hoses of the pipes communicating with the head side oil chamber of the offset cylinder 13.

FIG. 12 is a view seen from AA in FIG. In the figure, 32 is an oil passage communicating with the head-side oil chamber of the arm cylinder 11 (a pipe passage of a relay pipe 32B connecting the hydraulic hoses 26a and 26b), and 33 is oil communicating with the head-side oil chamber of the bucket cylinder 12. Road (hydraulic hose 2
7a and 27b are connected to the relay pipe 33B), and 34 is an oil passage communicating with the head side oil chamber of the offset cylinder 13 (the relay pipe 34B is connected to the hydraulic hoses 28a and 28b). , 38 are arm cylinders 1
1, an oil passage communicating with the rod-side oil chamber (a pipe communicating with the relay pipe 38R), 39 is an oil passage communicating with the rod-side oil chamber of the bucket cylinder 12 (a pipe communicating with the relay pipe 39R), Reference numeral 40 denotes an oil passage (a pipe passage communicating with the relay pipe 40R) communicating with the rod-side oil chamber of the offset cylinder 13.

Conventionally, in a side excavation work device equipped on a hydraulic excavator, a lower boom 5 (shown in FIG. 10) is used.
The offset boom 6 connected to the front part of the above forms a parallel link, and the arm 8 and the bucket 9 are offsetly moved to the left and right by expanding and contracting the offset cylinder 13. Further, in the working device for side edge excavation 4'in one embodiment of the prior art shown in FIG. 11, the pipe mounting device 24 is provided on the side surface of the lower boom 5 ', and the arm cylinder 11,
The hydraulic pipes for supply and discharge connected to the bucket cylinder 12 and the offset cylinder 13 are arranged in an orderly and accurate manner.

[0006]

In the work equipment for side excavation of the prior art, pressure oil from a hydraulic pump (a main pump (not shown)) mounted on an upper swing body of a hydraulic excavator is supplied. It is designed to be supplied to the offset cylinder through a discharge circuit. However, when the upper revolving structure is being revolved during the operation of the hydraulic excavator, for example, if the hydraulic oil is released to the outside due to an unexpected disconnection of the supply / discharge circuit, There is a risk that the work device becomes free from the offset state and is swung around. The present invention relates to the work of a construction machine in which a head-side holding function valve and a rod-side holding function valve are compactly provided to an offset cylinder arranged inside an offset boom of a side edge excavating work device. The purpose is to provide a device.

[0007]

According to the present invention, there is provided a lower boom pivotally attached to an airframe in a vertically swingable manner, an offset boom pivotally attached to a tip end of the lower boom in a laterally swingable manner, and An upper boom pivotally attached to the tip end of the offset boom so as to be swingable in the left-right direction, an arm pivotally attached to the upper boom so as to be swingable in the front-rear direction, and an offset boom that is arranged laterally of the offset boom. In a construction machine having an offset cylinder that swings in the left-right direction, a holding function valve capable of holding an oil tight state of a head side oil chamber and a rod side oil chamber of the offset cylinder is provided, and the holding function valve is the offset. Fixed to cylinder.

As a result, after operating the offset cylinder of the working device (working device for side digging) to set the required offset amount, both the head-side oil chamber and the rod-side oil chamber of the offset cylinder are It is kept oil-tight by the holding function valve. Therefore, when the upper revolving structure is being rotated during the operation of the hydraulic excavator, even if the supply / discharge circuit for the offset cylinder is disconnected due to some unexpected reason, the hydraulic oil is discharged to the outside. Is held in a fixed state, and it is possible to prevent the trouble of becoming a free state. Further, since the holding function valve is fixed to the offset cylinder, the arrangement of the holding function valve does not adversely affect the narrow layout space of the upper swing body. Further, at the time of assembling the working device, the offset cylinder and the holding function valve can be previously sub-assembled into an integrated type for efficient assembly. Also, check the offset cylinder, the holding function valve, etc. installed in the work equipment,
When performing repair or replacement, the tip end side of the offset boom of the working device can be easily moved down to near the ground, which is very convenient for maintenance.

Further, a holding function valve capable of holding the head-side and rod-side oil chambers of the offset cylinder in an oil-tight state is provided, and the holding function valve is arranged vertically with respect to the offset cylinder from the offset boom. It was fixed so that it would not protrude substantially. As a result, since the holding function valve does not project outside the upper surface and the lower surface of the offset boom forming the parallel link, it is possible to prevent an accident in which the holding function valve collides with an external obstacle. .

Further, the holding function valve is a head side holding function valve communicating with the head side oil chamber of the offset cylinder, and a rod side holding function valve communicating with the rod side oil chamber of the offset cylinder. Of the head side holding function valve and the rod side holding function valve, and a directional switching valve for controlling the operation of the head side holding function valve and an elastic pipe for communicating the holding function valve with an oil passage. The pipe connection port on the side is arranged so that it faces the fuselage side. As a result, the head-side oil chamber and the rod-side oil chamber of the offset cylinder can be surely maintained in the oil-tight state by the head-side holding function valve and the rod-side holding function valve, respectively. The elastic pipe can be efficiently and neatly arranged.

Further, the head-side holding function valve and the rod-side holding function valve are separately constructed and have the same shape, and the back surfaces of the head-side holding function valve and the rod-side holding function valve are combined. And attached to the offset cylinder. Accordingly, the holding function valve can be manufactured easily and inexpensively, and it is very advantageous in terms of assembling and maintaining the holding function valve with respect to the offset cylinder.

Further, the head-side holding function valve and the rod-side holding function valve are detachably attached to the offset cylinder by a band member wound around the offset cylinder. As a result, the assembling property and the maintainability of the both holding function valves with respect to the offset cylinder can be improved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a partially cutaway side view of a hydraulic excavator 1a equipped with a working device (working device for side edge excavation) 4a according to an embodiment of the present invention. In the figure,
2a is an upper revolving structure of the hydraulic excavator 1a, 3a is a lower traveling structure, 4a is a working device mounted on the front part of the upper revolving structure 2a, 5a is a lower boom of the working device 4a, 6a is an offset boom, 7a is an upper boom, 8a is an arm,
Reference numeral 9a is a bucket, 10a is a boom cylinder, 11a is an arm cylinder, 12a is a bucket cylinder, and 13a is an offset cylinder.

FIG. 2 is a main part hydraulic circuit diagram for the working device 4a mounted on the hydraulic excavator 1a. In the figure,
Reference numeral 14 is an engine that is a power source mounted on the upper revolving structure 2a, 15 is a hydraulic pump that is rotationally driven by the engine 14 and discharges main pressure oil, 16 is a pilot pump that discharges pilot primary pressure, and 29 is hydraulic oil. A tank, 30 is an offset pilot switching valve (hereinafter referred to as an offset directional switching valve) which is a directional switching valve for controlling the offset cylinder 13a, and 31 and 31 'are pilot ports of the offset directional switching valve 30 and 35, respectively.
H and 35R are head side oil chambers and rod side oil chambers of the offset cylinder 13a, and 36H and 36R are head side holding function valves capable of holding the head side oil chambers 35H and rod side oil chambers 35R in an oil tight state, respectively. , Rod side holding function valve (holding function valve is also called holding valve), 37H, 37R are head side holding function valve 3
6H, a logic valve provided to each of the rod-side holding function valves 36R for shutting off or opening the main hydraulic oil passage,
41H and 41R are pilot on-off valves that control the operation of the logic valves 37H and 37R, respectively, and 42 is an offset direction switching valve 30 and the pilot on-off valves 41H and 41.
Hydraulic remote control valve for offset for interlocking and switching R (lever operation type, pedal operation type), 43H, 4
3R is a supply / discharge pipe line (using a hydraulic hose that is an elastic pipe) that communicates the directional switching valve 30 for offset, the head side holding function valve 36H, and the rod side holding function valve 36R, and 44H is a supply line. The pipe connection port of the head side holding function valve 36H to which the discharge pipe line 43H is connected, and 44R is the rod side holding function valve 36 to which the supply and discharge pipe line 43R is connected.
This is the R pipe connection port.

In FIG. 3, in order to inspect the vicinity of the offset cylinder 13a in FIG. 1, the arm 8a is retracted and the tip end side of the offset boom 6a is moved to the ground (G.
L. ) Hydraulic excavator 1a showing the state of being lowered
FIG.

FIG. 4 is an enlarged view of portion B in FIG. In the figure, 36H and (36R) are the head side holding function valve and the rod side holding function valve (the rod side holding function valve 36R is on the opposite side of the head side holding function valve 36H, so they are not visible in the figure), 44H, ( 44R) are pipe connection ports of the head-side holding function valve 36H and (rod-side holding function valve 36R) (the pipe connection port 44R is on the opposite side of the pipe connection port 44H, and therefore cannot be seen in the drawing), 43
H and (43R) are pipe connection ports 44H and (4
4R) supply / discharge pipes (supply / discharge pipes 43H, 4
A hydraulic hose is used for 3R, but the supply / discharge line 43R
Is on the opposite side of the supply / discharge pipe line 43H, so it is not visible in the drawing.) 45 is a head-side holding function valve 36H and a rod-side holding function valve 36R that are detachably attached (by bolting) to the offset cylinder 13a. The band member (the band member 45 in this embodiment is made of a band-shaped thin steel plate.

FIG. 5 is a cross-sectional view of the principal part viewed from CC of FIG. FIG. 6 is a plan view of a main part viewed from DD of FIG.

Next, the construction and operation of the working apparatus 4a of this embodiment will be described with reference to FIGS. In this embodiment,
As shown in FIG. 1, a lower boom 5a pivotally attached to an upper swing body 2a so as to be vertically swingable, and the lower boom 5a.
An offset boom 6a pivotally attached to the tip of the shaft so as to be swingable in the left-right direction and forming a parallel link (the shape of the parallel link is shown in FIG. 3);
An upper boom 7a pivotally attached to the tip end of the offset boom 6a in the left-right direction, an arm 8a pivotally attached to the upper boom 7a in the front-rear direction, and an offset boom arranged inside the offset boom 6a. In the hydraulic excavator 1a having an offset cylinder 13a for swinging 6a in the left-right direction, the offset cylinder 13a
Of the head-side oil chamber 35H (shown in FIG. 2) and the rod-side oil chamber 35R in an oil-tight state, respectively, a holding function valve 36.
H and 36R (head side holding function valve 36H and rod side holding function valve 36R described later) are provided, and the holding function valves 36H and 36R are fixed to the offset cylinder 13a.

Although the holding function valves 36H and 36R are provided for the offset cylinder 13a as described above, when the working device 4a is operated to perform the offset operation, the operating lever of the offset hydraulic remote control valve 42 shown in FIG. 46 is operated from the neutral position N to the left or right as required. The pilot secondary pressure derived from the offset hydraulic remote control valve 42 acts on the pilot port 47H or 47R of the holding function valves 36H and 36R. The pilot opening / closing valve 41H in the holding function valves 36H and 36R,
Alternatively, 41R switches from the shutoff oil passage position to the opening oil passage position with the throttle portion, and the directional switching valve for offset 30 switches to the a position or the b position, so the offset cylinder 1
3a extends or contracts, and the work device 4a can be offset without any trouble.

As a result, after operating the offset cylinder 13a of the working device 4a to set the required offset amount (since the operating lever 46 of the offset hydraulic remote control valve 42 shown in FIG. 2 has been returned to the neutral position N). , The pilot opening / closing valves 41H in the holding function valves 36H, 36R,
41R, the logic valves 37H and 37R are all in the oil passage shutoff state), both the head side oil chamber 35H and the rod side oil chamber 35R of the offset cylinder 13a are kept in an oil tight state by the holding function valves 36H and 36R. Held in. Therefore, when the upper revolving superstructure 2a is revolving during the operation of the hydraulic excavator 1a, for example, for some unexpected reason, at least one of the supply / discharge pipe lines 43H, 43R (shown in FIG. 2) of the offset cylinder 13a is connected. Even when the oil is released and the hydraulic oil is discharged to the outside, the offset state is maintained in the fixed state, and it is possible to prevent the trouble of becoming the free state. Further, the holding function valve 36
Since H and 36R are fixed to the offset cylinder 13a, the arrangement of the holding function valves 36H and 36R is
It does not adversely affect the narrow layout space of the upper swing body 2a. Further, at the time of assembling the working device 4a, the offset cylinder 13a and the holding function valves 36H and 36R can be sub-assembled integrally in advance to perform efficient assembly. Further, the offset cylinder 13a and the holding function valve 3 which are assembled to the working device 4a.
When performing inspection, repair, or replacement of 6H, 36R, etc., as shown in FIG. 3, the tip side of the offset boom 6a of the work 4a can be easily moved down to near the ground. It is convenient for

Further, the holding function valves 36H and 36R are
It was fixed to the offset cylinder 13a so as not to substantially project from the offset boom 6a in the vertical direction. As a result, the holding function valves 36H and 36R do not project outside the upper surface c (shown in FIG. 5) and the lower surface d of the offset boom 6a forming a parallel link.
It is possible to prevent an accident in which the holding function valves 36H and 36R collide with an external obstacle.

Further, the holding function valve (36H, 36R)
Is a head side holding function valve 36H communicating with the head side oil chamber 35H of the offset cylinder 13a, and a rod side holding function valve 36R communicating with the rod side oil chamber 35R of the offset cylinder 13a.
An offset directional control valve 30 for controlling the operation of 3a;
The offset direction switching valve 30 and the holding function valve 36
H and 36R, which are elastic pipes (hydraulic hoses, which are referred to as supply and discharge pipe lines 43H and 43R), are connected to the head side holding function valve 36H and the rod side holding function valve 3.
The piping connection ports 44H and 44R on the side of the 6R offset directional control valve 30 are on the machine side (that is, on the upper swing body 2a side).
It was placed so that it faced to. As a result, the head side oil chamber 35H and the rod side oil chamber 35 of the offset cylinder 13a are
R can surely maintain an oil-tight state by the head-side holding function valve 36H and the rod-side holding function valve 36R, respectively, and the elastic pipe (supply / discharge as a hydraulic hose is connected to both holding function valves 36H and 36R). Pipe lines 43H, 4
3R can be piped efficiently and systematically.

Furthermore, the head-side holding function valve 36H and the rod-side holding function valve 36R are constructed separately and have the same shape, and the head-side holding function valve 3
6H and the rear surface of the rod-side holding function valve 36R were fitted together and mounted below the offset cylinder 13a. According to this, since the holding function valves 36H and 36R can be constituted by general-purpose holding function valves, it is not necessary to set a special holding function valve, the manufacturing can be performed at low cost, the parts management is easy, and the offset cylinder is used. Although the assemblability with respect to 13a is good, even if the holding function valves 36H and 36R are integrally formed, other functions can be provided, and the present invention is not limited to this. Not a thing.

Further, the head side holding function valve 36H and the rod side holding function valve 36R are offset cylinders by means of a band member 45 (in this embodiment formed by using a thin strip steel plate) wound around the offset cylinder 13a. 13a is detachably attached (by tightening bolts not labeled). This allows
It is possible to improve the assembling property and the maintainability of the both holding function valves 36H and 36R with respect to the offset cylinder 13a.

Although the holding function valves 36H and 36R in the present embodiment shown in FIGS. 4 to 6 are mounted below the offset cylinder 13a, they may not be mounted only below. FIG. 7 shows another embodiment holding function valve 3
FIG. 6 is a side view of a main portion showing a mounting state with respect to an offset cylinder 13b of 6′H, 36′R (the offset cylinder 13b is shown by an imaginary line for the sake of clarity). In the figure, 44'H and 44'R are the respective piping connection ports of the holding function valves 36'H and 36'R, and 43 '.
H and 43'R are pipe connection ports 44'H and 4 respectively
Each of the supply / discharge pipe lines (which is a hydraulic hose as an elastic pipe) connected to 4'R, and 45 'is a band member (the material is a band-shaped thin steel plate).

FIG. 8 is a view seen from EE in FIG.
FIG. 9 is a plan view of an essential part seen from F in FIG. 7. In another embodiment, as shown in FIGS. 7 to 9, the holding function valves 36'H, 3
6'R is attached above the offset cylinder 13b. Although the offset boom to which the offset cylinder 13b is attached is not shown, there is no risk of collision with the holding function valves 36'H, 36'R or the upper arm cylinder.

[0027]

According to the present invention, in a hydraulic excavator (construction machine) equipped with a working device for excavating a side edge, the offset cylinder is provided with respect to the offset cylinder disposed inside the offset boom of the working device. A holding function valve capable of holding the oil tight state of the head side oil chamber and the rod side oil chamber was fixedly attached. According to this, after the offset cylinder is operated to set the required offset amount, both the head-side oil chamber and the rod-side oil chamber of the offset cylinder are held in the oil-tight state by the holding function valve. . Therefore, when the upper revolving structure is being rotated during the operation of the hydraulic excavator, even if the supply / discharge circuit for the offset cylinder is disconnected due to some unexpected reason, the hydraulic oil is discharged to the outside. Is held in a fixed state, and it is possible to prevent the trouble of becoming a free state. Further, since the holding function valve is fixed to the offset cylinder, the arrangement of the holding function valve does not adversely affect the narrow layout space of the upper swing body. Further, at the time of assembling the working device, the offset cylinder and the holding function valve can be previously sub-assembled into an integrated type for efficient assembly. Also, when inspecting, repairing, or replacing the offset cylinder, the holding function valve, etc. assembled to the working device, it is easy to lower the tip end side of the offset boom of the working device to near the ground. Because it is possible, it is very convenient for maintenance.

Further, since the holding function valve is fixed to the offset cylinder so as not to substantially project from the offset boom in the vertical direction, it is possible to prevent the holding function valve from colliding with an external obstacle. be able to. Further, the holding function valve is a head side holding function valve that communicates with the head side oil chamber of the offset cylinder, and a rod side holding function valve that communicates with the rod side oil chamber of the offset cylinder. An elastic pipe (hydraulic hose) as an oil passage connecting the directional control valve for controlling the directional control valve and the holding function valve, and the head side holding function valve and the rod side holding function valve on the directional switching valve side. Since the pipe connection port is arranged so as to face the machine side, the head side oil chamber and the rod side oil chamber of the offset cylinder are surely kept oil tight by the head side holding function valve and the rod side holding function valve, respectively. At the same time, the elastic pipe can be efficiently and orderly piped to both the holding function valves.

Further, the head-side holding function valve and the rod-side holding function valve are constructed separately and have the same shape, and the rear surfaces of the head-side holding function valve and the rod-side holding function valve are In addition, since the holding function valve is attached to the offset cylinder, the holding function valve can be manufactured easily and inexpensively, and it is very advantageous in terms of the assembling property and the maintainability of the holding function valve with respect to the offset cylinder.

Further, the head-side holding function valve and the rod-side holding function valve are detachably attached to the offset cylinder by a band member wound around the offset cylinder. It is possible to improve the assembling property and the maintainability of the offset cylinder.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a hydraulic excavator equipped with a working device according to an embodiment of the present invention.

FIG. 2 is a main part hydraulic circuit diagram for a work device equipped in the hydraulic excavator shown in FIG.

FIG. 3 is a front view of the hydraulic excavator showing a state in which the tip end side of the offset boom in FIG. 1 is lowered to near the ground.

FIG. 4 is an enlarged view of part B in FIG.

5 is a main-portion cross-sectional view as seen from CC in FIG. 4;

FIG. 6 is a plan view of an essential part seen from DD of FIG.

FIG. 7 is a side view of essential parts showing a mounting state of a holding function valve of another embodiment of the present embodiment with respect to an offset cylinder.

FIG. 8 is a diagram viewed from EE in FIG. 7.

FIG. 9 is a plan view of an essential part seen from F in FIG.

FIG. 10 is a side view of a hydraulic excavator which has been used more often than before.

FIG. 11 is a side view of a main part of a side edge excavating work device according to an embodiment of the related art.

FIG. 12 is a view seen from AA in FIG. 11.

[Explanation of symbols]

1,1a Hydraulic excavator 4,4 ', 4a Working device (working device for side digging) 5,5', 5a Lower boom 6,6a Offset boom 7,7a Upper boom 8,8a Arm 13,13a, 13b Offset cylinder 30 Offset Direction switching valve 35H Head side oil chamber 35R Rod side oil chamber 36H, 36R, 36'H, 36'R Holding function valve 43H, 43R, 43'H, 43'R Supply / discharge pipe line (elastic pipe) 44H, 44R , 44'H, 44'R Piping connection port 45, 45 'Band member

Claims (5)

[Claims] 1. A lower boom pivotally attached to an airframe so as to be swingable in the vertical direction, an offset boom pivotally attached to the tip of the lower boom so as to be swingable in the left-right direction, and a left-right direction to the tip of the offset boom. An upper boom pivotally pivoted, an arm pivotally pivoted to the upper boom in the front-rear direction, and an offset cylinder arranged laterally of the offset boom for pivoting the offset boom left and right. A construction machine having a holding function valve capable of holding the oil tight state of the head side oil chamber and the rod side oil chamber of the offset cylinder, and the holding function valve is fixed to the offset cylinder. A characteristic working device for construction machinery. 2. A lower boom pivotally attached to the airframe so as to be vertically swingable, an offset boom pivotally attached to the tip of the lower boom so as to be pivotable in the left and right directions, and a left and right direction to the tip of the offset boom. An upper boom pivotally pivoted, an arm pivotally pivoted to the upper boom in the front-rear direction, and an offset cylinder arranged laterally of the offset boom for pivoting the offset boom left and right. And a holding function valve capable of holding the head-side and / or rod-side oil chamber of the offset cylinder in an oil-tight state, the holding function valve having the offset boom with respect to the offset cylinder. A working device for a construction machine, wherein the working device is fixed so as not to substantially vertically project from the work device. 3. The holding function valve is a head side holding function valve communicating with the head side oil chamber of the offset cylinder, and a rod side holding function valve communicating with the rod side oil chamber of the offset cylinder. The head-side holding function valve and the rod-side holding function valve have the directional switching valve for controlling the operation of the cylinder, and the elastic pipe for communicating the directional switching valve with the holding function valve in an oil passage. The work device for a construction machine according to claim 1 or 2, wherein the pipe connection port on the valve side is arranged so as to face the machine body side. 4. The head-side holding function valve and the rod-side holding function valve are separately configured and have the same shape, and the head-side holding function valve and the rod-side holding function valve are provided with rear surfaces. In addition, the working device for a construction machine according to claim 3, wherein the working device is attached to the offset cylinder. 5. The head-side holding function valve and the rod-side holding function valve are detachably attached to the offset cylinder by a band member wound around the offset cylinder. The working device of the described construction machine.