EP0014776B1 - Rock cutter jib - Google Patents

Description

The present invention relates to a lifting arm fitted to a rock cutting device.

The cutting devices are generally intended to make notches in rock layers, perpendicular to the felling front. To this end, the cutting devices often comprise at least one endless cutting chain, composed of links carrying outwardly cutting elements and driven by a motor.

We know, in particular from the German patent 895.883, a cutting device in which each cutting chain carrying guide pads is mounted on a chassis constituting a cutting arm, formed of parallel beams or plates carrying at their ends respectively a wheel drive and a deflection wheel.

In the side walls of the lifting arms of this known device are formed several fluid spraying lines, generally water, in order to avoid the formation of dust when notching the rock layers. However, these machines have the disadvantage of not distributing the fluid uniformly over the entire surface of the chain and in particular of not lubricating the guide shoes.

The arrangement of pipes and spray heads in the side walls of the lifting arms requires, moreover, a complex construction thereof.

DE-U-7 425 867 describes a cutting device similar to the devices described above. To avoid obstruction of the pipes, especially in the vicinity of the gear wheel of the endless chain, the spray heads are arranged in the vicinity of the part of the chain driven towards the cutting zone and directed towards it. This arrangement is nevertheless difficult to achieve given the small thickness of the side walls of the lifting arm and the lack of space available between them.

Another disadvantage of the known devices mentioned above results from the use of an endless chain intended to carry and transport the cutting elements. This chain is expensive both in terms of its construction and its maintenance.

The object of the invention is a new lifting arm of particularly simple construction, devoid of the aforementioned disadvantages.

The lifting arm according to the invention, fitted to a rock cutting device and comprising parallel beams, at the ends of which are mounted respectively a drive wheel and a return wheel of an endless element carrying externally cutting elements and internally guide shoes sliding in a groove, is essentially characterized in that the endless element consists of a belt internally carrying guide shoes each consisting of a block extending over the entire width of the aforementioned groove, the bottom of which comprises injectors supplying a fluid which is spread there by the moving pads to form a sheet of fluid completely covering the bottom of this groove in order to allow the pads to slide on this sheet.

According to a feature of the invention, the injectors arranged in the bottom of the groove of each spar, advantageously communicate with two hollow spaces which are located on either side of a core of each spar, these spaces being delimited by this side member and side plates and being connected to a water supply.

• elle permet la pulvérisation d'eau au voisinage immédiat de la zone de coupe;
• elle assure un refroidissement efficace de l'outil de coupe;
• elle permet une répartition uniforme du fluide sur toute la largeur des patins de guidage;
• elle diminue les frottements des patins de guidage contre la rainure de chaque longeron et donc l'usure de ces patins de guidage;
• elle empêche la formation de poussières lors du fonctionnement de a machine;
• elle empêche l'obstruction des injecteurs;
• elle éloigne les débris pierreux pouvant venir se loger dans la rainure susdite, et
• elle permet une construction simple et compacte du bras haveur.

This particular arrangement of the water supply pipe and the injectors in the lifting arm according to the invention provides the following advantages:

• it allows the spraying of water in the immediate vicinity of the cutting zone;
• it ensures efficient cooling of the cutting tool;
• it allows a uniform distribution of the fluid over the entire width of the guide shoes;
• it reduces the friction of the guide shoes against the groove of each spar and therefore the wear of these guide shoes;
• it prevents the formation of dust during machine operation;
• it prevents blockage of the injectors;
• it removes stony debris that may come to lodge in the above-mentioned groove, and
• it allows a simple and compact construction of the lifting arm.

To further facilitate the sliding of the blocks of the guide pads of the new lifting arm on the fluid sheet, the anterior edge of the sliding face of each of these blocks against the bottom of the grooves is rounded.

In order to firmly secure the blocks of the guide shoes to the endless belt of the new lifting arm, these blocks each extend transversely over a large part of the width of this belt.

In order to easily build the guide grooves of the new lifting arm, these grooves are each delimited by the external face of the corresponding spar and by two side plates projecting from this face.

To effectively guide the endless belt with respect to the control and return wheels of the new lifting arm, the guide shoes are engaged on the periphery of each of these wheels, between two lateral guide plates whose spacing distance is substantially equal to the width of the side member grooves.

Advantageously, in the new lifting arm, the mounting face of the communication wheel Mande, on which the blocks of the guide shoes are successively applied, is provided with a rough coating for example of hard rubber.

To ensure continuity between the bottom of the grooves of the side members and the face for laying the blocks of the guide shoes in the idler wheel, the ends of these side members, adjacent to this wheel, include fixed combs extending these side members into grooves corresponding circulars provided in this laying face of this idler wheel.

• La figure 1 est une vue en élévation avec coupe partielle d'un bras haveur selon l'invention.
• Les figures 2, 3 et 4 sont des demi-coupes du bras haveur, faites respectivement suivant les plans II-II, III-III et IV-IV de la figure précédente.
• La figure 5 est une vue en perspective partielle du bras haveur.
• La figure 6 est une vue en perspective partielle explosée de l'extrémité d'un longeron et d'une partie de la roue de renvoi du bras haveur.

Other details and particularities of the invention will emerge from the detailed description which follows, with reference to the attached drawings, in which:

• Figure 1 is an elevational view in partial section of a lifting arm according to the invention.
• Figures 2, 3 and 4 are half-sections of the lifting arm, made respectively along the planes II-II, III-III and IV-IV of the previous figure.
• Figure 5 is a partial perspective view of the lifting arm.
• Figure 6 is an exploded partial perspective view of the end of a beam and part of the deflection wheel of the lifting arm.

In these different figures, the same reference notations designate identical elements.

The lifting arm shown comprises a frame 1 in one piece in the form of a welded construction.

The frame of the chassis 1 consists essentially of an upper beam 2, a lower beam 3 and spacers 4 .. The frame is covered on both sides by side plates 5 and 6.

The upper spar 2- is formed by an I-shaped beam whose inner and lower sole 7 is thicker than the outer and upper sole 8, which has an outer or upper face 9. The lateral sheets 5 and 6 project towards the up the face 9 of the spar 2, so as to form an upper groove 10 whose width is thus equal to that of this spar 2. The upper spar 2 comprises upper injectors 11 mounted in the upper sole 8 and communicating respectively with the two hollow spaces 12 and 13 located on either side of the spar 2 and delimited by this spar 2 and the sheets 5 and 6. The space 12 is connected to a water supply, in particular by a lateral supply pipe not shown, carried by the sheet 5 and by a flexible pipe also not drawn. The space 13 is connected to the same water supply by analogous means. In this way, the upper injectors 11 can bring water to the upper face 9 of the spar 10.

Similarly, the lower spar 3 is formed by an identical I-shaped beam but arranged inversely. Therefore, the inner and upper sole 14 is pleated thicker than the outer or lower sole 15 which has an outer or lower face 16. The side plates 5 and 6 project downwards above the face 16 above, so as to form a groove. lower inverse to the previous 10.

Like the upper spar 2, the lower spar 3 is equipped with lower injectors identical to the previous 11 and mounted in the same way in the lower sole 15. The lower injectors communicate respectively with the two opposite hollow spaces which are delimited by the spar 3 and the sheets 5 and 6 and which are connected to the water supply by means similar to the above. Thus, the lower injectors can bring water flush with the lower face 16 of the spar 3.

One end of the chassis 1 carries a control wheel or pulley 17 rotating around a rotation axis 18 under the action of a motor 19. The control wheel 17 comprises a plain web 20 which has a uniform thickness and which is mounted by screws 21 on a plate 22. The plate 22 is mechanically connected to the output shaft of the motor 19, the casing of which is secured to the side plate 6 by conventional means. The circumferential periphery of the web 20 is lined with a rough coating 23, for example of hard rubber. It should be noted that the ends. semicircular side plates 5 and 6 exceed the garment 23 and therefore form therewith a hollow space 24 of rectangular radial section. This space 24 actually corresponds to the grooves of the side members 2 and 3 and is connected to these grooves. As protection, the edges of the semi-circular ends of the sheets 5 and 6 carry a welded cover 25. The opposite end of the chassis 1 carries a wheel or a return pulley 26 of the belt freely rotating about an axis of rotation 27 parallel to the previous 18. In fact, the return wheel 26 is formed by a ring 28 mounted by by means of a ball ring 29 on a fixed hub made up of two discs 30 and 31 joined together by screws 32 and at the corresponding semi-circular ends of the sheets 5 and 6 by other screws 33. The construction and the mounting of the deflection wheel 26 and of the abovementioned hub can easily be understood with reference to FIG. 4. The semi-circular ends of the sheets 5 and 6 extend beyond the periphery of the ring 28 and therefore form with it a hollow space 34 of rectangular section. This space 34 corresponds to the grooves of the side members 2 and 3 and is moreover connected to the grooves in question, using combs 35 well illustrated in FIG. 6. the combs 35 are fixed to the corresponding ends of the beams constituting the side members 2 and 3 and their teeth are engaged with play in appropriate circular grooves 36 of the device of the ring 28.

On the drive wheels 17 and return 26 is mounted an endless belt 37 having a flat rectangular section. The belt 37 internally carries guide shoes 38 and externally clamping plates 39 provided with transverse cutting elements 40. The belt 37 is therefore movable along the longitudinal members 2 and 3 under the action of the motor 19.

The guide shoes 38 are parallelepipedal blocks of synthetic material. Each block extends over a large part of the belt 37 and practically over the entire width of the groove 10 longitudinal members 2 and 3. The front edge 41 of the face of the block, which is opposite to that placed against the belt 37, is rounded as illustrated in FIG. 5. Furthermore, each block is fixed to the belt 37 by fixing screws 42 inserting this belt 37 between this block and the clamping plate 39.

The cutting elements 40 are generally in diamond concretion and slightly protrude in transverse direction the clamping plate 39 and the belt 37.

When running, the belt 37 is moved along the side rails 2 and 3 and around the control wheels 17 and the return wheel 26. The guide shoes 38 then slide in the grooves of the side rails 2 and 3 and bear without sliding against the garment 23 of the wheel 17 and the ring 28 of the wheel 26, between the marginal parts of the side plates 5 and 6. Simultaneously with the movement of the belt 37, water flows are brought by the upper injectors 11 and lower on the end faces 9 and 16 of the beams of the side members 2 and 3. Under the effect of the rapid translation of the guide shoes 38 in the above-mentioned grooves, the injected water flows are spread over the external faces 9 and 16 and form there aquaplaning surfaces substantially reducing the friction of these pads 38 against these faces 9 and 16. In this way, the energy absorbed for the movement of the belt 37 is largely used for cutting rocks by the cutting elements 40.

Claims (8)

1. A cutting arm for a rock cutting apparatus, comprising a frame structure (1) bordered by longitudinal members (2,3), at the ends of which there are respectively mounted a drive wheel (17) and a return wheel (26) of an endless member (37) which externally carries cutting members (40) and which internally carries guide shoes (38) slidable in a groove (10), characterised in that the endless member comprises a belt (37) which internally. carries guide shoes (38), each of which comprises a block extending over the entire width of said groove (10), the bottom (9 and 16) of which has injectors (11) for supplying a fluid which is spread out therein by the shoes (38) in movement thereof to form a layer of fluid which completely covers said groove (10), for permitting sliding movement of the shoes on said layer of fluid.

2. A cutting arm according to claim 1 characterised in that the injectors (111 which are provided in the bottom (9, 16) of the groove (10) communicate with two hollow spaces (12 and 13) which are disposed on respective sides of a central web portion of each longitudinal member (2), said spaces being defined by said . longitudinal member (2) and plate members (5 and 6) and being connected to a water supply.

3. A cutting arm according to claim 1 or claim 2 characterised in that the leading edge (41) of the sliding face of the block of each guide shoe (38) with which the block slides against the bottom (9 and 16) of the grooves (10) is rounded.

4. A cutting arm according to any one of claims 1 to 3 characterised in that the block of each guide shoe (38) extends transversely over a large part of the width of the belt (37).

5. A cutting arm according to any one of claims 1 to 4 characterised in that the groove (10) of the upper longitudinal member (2) and the lower longitudinal member (3) respectively is defined by the outside face (9 and 16 respectively) of said longitudinal member and by two side plates (5 and 6) projecting beyond said face (9 and 16 respectively).

6. A cutting arm according to any one of claims 1 to 5 characterised in that the guide shoes (38) are engaged to the periphery of the actuating wheel (17) and the return wheel (26) respectively between two side guide plate members (5 and 6), distance between which is substantially equal to the width of the grooves (10) of the longitudinal members (2 and 3).

7. A cutting arm according to any one of claims 1 to 6 characterised in that the support surface of the actuating wheel (17), against which the blocks of the guide shoes. (38) are successively applied, is lined with a rough covering (23), for example of hard rubber.

8. A cutting arm according to either one of claims 6 and 7 characterised in that the ends of the longitudinal members (2 and 3), which are adjacent to the return wheel (26), comprise fixed comb members (35) which extend said longitudinal members (2 and 3) into corresponding circular grooves (36) provided in the support surface for supporting the blocks of the guide shoes (38) on said wheel (26).

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