Safe driver's cab arrangement for a mobile earth-moving machine

The present invention relates to a safety cabin for working machines, in particular for working in mines.

A cabin is known to withstand the forces and loads applied to it only when specifically required. For this purpose, a cabin with a particularly robust structure capable of withstanding the loads exerted on it is used. A variation of this heavy cabin is a lightweight cabin, around which a truss is built, which directly takes the load that is to withstand under load. An important feature of both systems is that the cabin is protected by a separate, safe structure. This structure can be made of both brackets and safety ribs and is attached in any elasticity to the frame of the tool. This structure protects the safety cabin beneath it and is generally flexibly mounted on the implement frame. Even this structure is massive and takes up a lot of space.

The cabin itself cannot withstand the forces specified in the safety standards. For an earth-moving implement where the operator sits to the side of the implement, the structure described above increases the height and width of the implement. Using larger tools, for example, requires larger tunnels in the mine, which is extremely costly. Therefore, it is necessary to use a smaller tool, which reduces the payload and increases the total cost of shifting blasted rock.

It is also a characteristic of this type of structure when used with an earth-moving implement that ordinary maintenance and repair of the equipment becomes more difficult as the protective structures are placed in the maintenance and repair area. The attached securing ribs and securing trusses also complicate maintenance operations as they are usually difficult to disassemble.

In LHD type implements and mining dumpers, the cab is usually installed on the side of the longitudinal axis of the machine and, moreover, on LHD implements the operator usually sits sideways. Approved cabins are required to conform to existing standards. Moreover, safety cabins are required to comply with

174 838 the so-called ROPS standards and FOPS standards (rollover protection and falling objects protection structure).

In some countries, national requirements are also imposed on safe LHD implement cabins. Overall, these standards and requirements dictate that, in the event that a machine overturns, a sufficiently large, safe space must be left for the operator. Moreover, the standards require laboratory tests to be performed by an officially approved testing institute where the cabin is loaded both transversely and longitudinally and from above. A cabin subject to transverse loads is required to withstand the applied force and its design is required to absorb a certain amount of energy. In addition, the cabin is also required to withstand a force applied vertically and longitudinally. The absolute value of the forces and the energy charge are determined by the weight of the machine. As a result, the heavier the machine is, the greater the forces it should withstand. During the aforementioned tests, changes to the cab shape must remain small enough so that the safe space for the operator remains intact.

The patent description SU 695 871 discloses a solution in which a safety cabin is attached to a machine. The safety bar assembly is attached to the outside around the work room. The bar set secures the working room against external stresses. The safety bar assembly surrounds, but is not connected to, the work room. Therefore, the forces which act directly on the walls of the work room are not damped by the securing bar assembly but only by the work room itself. In such cases, the working room may be crushed and does not protect the operator, because the room is not additionally secured against these forces with safety bars.

A tractor cab is known from DE Patent No. 2,827,614. Outside, the cabin is surrounded by a cage of bars. The cage is attached to the tractor and the cab is placed inside and attached to the cage. In this solution, the cabin is not designed to absorb and dampen any forces, the cage is used for this, and the cabin itself protects the operator from other inconveniences and protects the operator from falling out in the event that the tractor overturns.

From US Patent No. 3,791,668, a safety device against overturning of a cabin with deformable supports is known. In this solution, beams are used which are joined together above the vehicle in such a way that the beams, when the machine overturns, deform plastically but do not break. In this solution, the work room is not secured by any securing bars connected to it.

The greatest disadvantage of these safety cabins or guards was often that they did not meet the new requirements. When a cabin is designed according to the latest requirements, it becomes very heavy and bulky. The use of separate ribs and securing trusses makes the machine bulky and inconvenient to use in confined spaces. Moreover, the designs of the safety ribs and safety trusses interfere with the normal maintenance of the machine as described above. A cabin equipped with safety ribs and safety gratings, or a cabin with a special reinforcement, is often very expensive to implement.

A safety cabin for working machines, especially for working in mines, comprising a working room limited by interconnected roof, floor and side plates connected to an external safety bar and equipped with fastening elements connecting this working room with the machine according to the invention, characterized in that the safety bar has L-shaped and includes at least one angle, one end of which is connected to the work room, and the other end is attached to the machine.

Preferably, the safety bar is connected to the work room via reaction bars equipped with dampers.

Preferably, the safety bar is slidably fastened to the machine with at least one fastening element and is rotatably fastened by a bolt placed in a fastening bracket attached to the machine.

Preferably, the safety bar is in the form of box girders.

174 838

The most important advantage of the invention is that a safe cabin or enclosure, meeting the requirements of existing standards, can be built in quite a small space. The designs of the earlier cabins can be used in the solution according to the invention. The solution according to the invention can be used in conjunction with a cabin of older type machines. Safety bars installed outside the cabin absorb the forces, absorb energy, act as elastic elements, damping the shocks of the cabin.

The size of the machine is as small as possible, for this reason the blasted rock can be thrown in tunnels or similar spaces with the equipment of maximum capacity. It is also possible to provide a cabin that is both soundproof and shockproof or a shockproof open cabin. Moreover, the machine is easy to maintain and repair. Safety devices also do not take up additional space.

The subject of the invention in an exemplary embodiment is shown in the drawing, in which fig. 1 shows a side view of a tool equipped with a safety cabin, fig. 2 - top view of a tool equipped with a safety cabin, fig. 3 - side view of a safe cabin equipped with one bar Fig. 4 - front view of a safety cabin equipped with one safety bar, Fig. 5 - top view of a safety cabin equipped with one safety bar, fig. 6 - side view of a safe cabin equipped with two safety bars, fig. 7 - front view of a safe cabin equipped with two safety bars, fig. 8 - top view of a safe cabin equipped with two safety bars, fig. 9 - schematic view of a safety bar Fig. 10 is a schematic view of a safety bar used in conjunction with a safety car equipped with two safety bars. Fig. 11 is a detailed view of the attachment of the underside of the safe car to the machine.

The safety cabin is fixed on the machine 1. The cabin has a working room 2 intended for the machine operator 1 limited by interconnected roof 4, floor 5 and side panels 6. Side panels 6 are equipped with windows 7. A safe space 8 for the operator is marked in Fig. 3,4,6,7 with hatching. The work room on the side of the floor plate 5 is attached to the machine 1 by elastic fasteners 9. The safety bar 3 is made of interconnected plates 10 and is in the form of a box girder. Attached to the arm of the safety bar 3 are brackets 11 and 12 for fastening the safety bar to the work room 2 and to the machine 1. One of the arms of the safety bar 3 ends with a projection 13 which also serves to fasten the bar 3. The safety bar 3 and the brackets 11 and 12 are provided with holes 14, 15, 16, 17 for the fastening of the reaction rods 22, 23. A bracket 18 is attached to the machine 1, to which, by means of a bolt 24, the safety bar 3 is attached at the bend point. . The protrusion 13 of the safety bar is attached to the machine 1 by a sliding fastener 19. The reaction bars 22 and 23 are attached to the brackets 20 and 21 located in the upper part of the working room

2. The flexible fasteners in the reaction bars 22 and 23 are marked with the number 25 and act as shock absorbers. The work room 2 is installed by means of an external safety bar 3, which absorbs both transverse and longitudinal forces and absorbs energy from the transverse forces.

In figures 3 to 8 the forces acting on the safety cabin 2 are represented by arrows. The forces F to be withstand by the structure are transmitted through the frame of the working room to 2 safety bars 3. The frame of the room 2, with its attachments, must independently withstand the vertically applied load. The safety bar 3 is L-shaped when viewed from the side, and if only one safety bar 3 is used, it is L-shaped also when viewed in the longitudinal direction, and is attached at two points of its lower end to the frame. Under load conditions, the upper end of the safety bar 3 rests against the roof plate 4 of the working room 2. The work room 2 is attached to the upper end of the safety bar 3 by means of reaction bars 22 and 23, and rubber pads 25, which damp horizontal forces during normal use. The safety bar 3 absorbs the given energy by bending both its horizontal and vertical parts, so high flexibility is ensured with the small dimensions of the cabin 2.

174 838

The work room 2 may be reinforced with one or more safety bars 3. In the embodiment with two safety bars 3, bars are installed on both the front and rear corner of the work room 2. The transverse force is distributed evenly on both bars 3.

In the embodiment with one safety bar 3, the bar is installed at the front corner of the work room 2 according to the design of the room 2 and the machine frame 1. This system facilitates the maintenance of the machine 1 and minimally reduces the operator's field of vision. In the upper part of the working room 2 there is a longitudinal beam which, under load conditions, rests along its entire length against the roof plate 4 of the room 2. As the safety bar 3 is installed on the side of the longitudinal axis of the room 2, the vertical part of the safety bar 3 is also reinforced to prevent twisting of the room 2. The work room 2, equipped with the safety bar 3, has passed the required laboratory tests.

The essential feature of the present solution is that the structure comprises a work room or enclosure 2 which is strong enough to transmit the required forces to one or more separate safety bars 3 and to the machine frame 1. The forces are controlled by the interaction of the work room 2 and the separate ones. safety bars 3.

The sound and shock-proof work room 2 is attached to both the machine frame 1 and the safety bars 3 by flexible clamping elements 9 and 25. When high forces are applied to the work room frame 2, the elastic clamping elements 25 give way. under the action of a force, the forces are then transferred by mechanical fasteners to the safety bar (s) 3 and to the machine frame 1.

The safety cabin can be mechanically fastened to the frame of the machine 1 in different ways and at different points, and the attachment points and fasteners of the safety bar 3 can change according to the requirements of the shape of the working room 2.