Scraper assembly

Abstract

An excavator assembly which includes an excavator, a hydraulic hammer which is connected to an excavator arm, which has an impact member, which extends through an impact axis and which is operable by activation of the excavator arm to break rocks, and a scraper assembly for scraping broken rocks, wherein the scraper assembly includes a plurality of scraper elements which are releasably mounted to the frame at respective locations which are spaced apart from each other, on a straight orientation line or on a curved orientation line, and a method of operating said excavator assembly.

Description

SCRAPER ASSEMBLYBACKGROUND OF THE INVENTION

[0001] This invention relates to a scraper assembly for use with an excavator to form an excavator assembly, and to a method of using said excavator assembly to break rock, and to scrape broken rocks from a site thereby to dress or smooth a surface of the site.

[0002] The term “excavator” as used herein includes any machine which is configured to dig and move earth or which is configured to break rock and remove broken rocks from a site e.g. a construction site.

[0003] One form of an excavator assembly includes an excavator with an excavator arm and a hydraulic hammer which has a chisel at one end thereof, and which is connected to the excavator arm. The excavator arm can be operated to bring the chisel into contact with a rock, and to operate the hydraulic hammer to break the rock with a repetitive impact force. A user then typically operates the excavator arm to move the hydraulic hammer to scrape broken rocks from a site with the chisel. The removal of the broken rocks is an inefficient and time consuming process.

[0004] Additionally, it is sometimes difficult for the user to position the hydraulic hammer relative to a rock without causing the rock to move. This leads to more inefficiencies in the rock breaking process.

[0005] Some rocks are large and a considerable period maybe required to break such a rock into sufficiently small pieces for removal, and then to move the rock pieces away from the site.

[0006] “Rock” in the context of this invention includes any natural occurring mineral material which forms a part of the surface of the earth, an artificially or human made construct e.g. a concrete slab or structure, a concrete pillar, walls, asphalt on road surfaces or the like. The invention is not limited in this respect.

[0007] An object of the present invention is to address at least to some extent the aforementioned situation.SUMMARY OF THE INVENTION

[0008] The invention provides in a first instance a scraper assembly which includes a frame which is attachable to, or integrally formed in a body of a hydraulic hammer and at least one scraper element which is mounted to the frame.

[0009] In one form of the invention, the frame includes a pair of guide members which are opposed to and spaced apart from one another, for guiding the scraper element between a first position and a second position at which the scraper element is actuable to scrape broken rocks, or to hold a rock in place for breaking.

[0010] The scraper element may comprise at least one metal plate.

[0011] The scraper assembly preferably includes a holding mechanism which is configured to hold the scraper element in the first position and which is operable to release the scraper element to allow the scraper element to move to the second position.

[0012] The holding mechanism may comprise a mechanical fastener or, in the case where the scraper element is made from a metallic material, an electromagnetic assembly which is actuable to generate a magnetic field thereby to hold the scraper element in place.

[0013] The scraper element may be moved between the first position and the second position by means of a hydraulic actuator, or under gravitational action. In the case where hydraulics are not used, the scraper element can be moved from the second position to the first position by urging a lower end of the scraper element on a hard surface e.g. a rock.

[0014] The scraper element preferably comprises a metal plate, which is shaped according to requirement, and which has at least one stopper which projects from the metal plate, and which is located in a respective groove which is formed in one of the guide members, or in a surface of the body of the hydraulic hammer which faces the metal plate, for preventing the metal plate from moving past the second position.

[0015] The scraper element may comprise a first metal plate, a second metal plate which is spaced apart and which opposes the first metal plate, and two bridging structures which extend between respective ends of the metal plates such that a gap is formed between the metal plates, and a respective pair of projections which extend from each side of the hydraulic hammer and which are located within the gap thereby to guide the scraper element between the first position and the second position, and wherein the projections are configured to prevent the scraper element from moving past the first position or the second position.

[0016] In another form of the invention, the scraper assembly includes a plurality of the scraper elements which are mounted spaced apart from each other to the frame. For example and according to requirement 2, 4, or 6 scraper elements may be mounted to the frame at locationswhich are spaced apart from one another. It therefore falls within the scope of the invention to vary the quantity of scraper elements which are mounted to the frame.

[0017] The scraper elements may be orientated relative to each other in any suitable configuration e.g. the scraper elements may be spaced apart from one another on a straight orientation line or on a curved orientation line. The orientation line, when the scraper assembly is attached to the hydraulic hammer, may extend from the hydraulic hammer at any suitable angle, and preferably is perpendicular to the hydraulic hammer.

[0018] Each scraper element or a portion thereof is preferably releasably mounted to the frame so that if the scraper element breaks during operation it is easily replaceable by another scraper element of the same kind.

[0019] Each scraper element may comprise a respective biasing element and a respective scraping member with a leading end and a trailing end.

[0020] In one form of the invention, each biasing element comprises a hydraulic cylinder from which the scraping member extends.

[0021] In another form of the invention, each biasing element comprises a respective helical metal coil spring which has a first end which is secured to a location on the scraping member and a second end, and which defines a volume through which the scraping member extends.

[0022] The frame may comprise first and second support elements which are attachable to locations on an outer surface of the hydraulic hammer, so that when attached to the hydraulic hammer the first support element and the second support element are spaced apart and oppose one another.

[0023] The first support element and the second support element may be connected to each other thereby to form a U-shape.

[0024] Each support element may include a respective plurality of spaced apart apertures through which the scraper elements extend.

[0025] The respective first ends and respective second ends of the biasing elements preferably abut portions of respective surfaces of the support elements which face each other.

[0026] The biasing elements are preferably located between the support elements.

[0027] Each scraper element may be movable between a rest position and a limiting position.

[0028] Each scraping member is preferably movable between a rest position, at which the respective biasing element extends substantially along a length of a portion of the scraping member which is between the support elements i.e. the respective first ends and respective second ends of the biasing elements abut portions of the respective surfaces of the support elements, and a limiting position at which the coil is fully compressed.

[0029] Each biasing element is preferably configured to urge the respective scraping member in a first direction away from the at least one support element towards the respective rest position in response to a force acting on the scraping member in a second direction which is opposite to the first direction towards the respective limiting position.

[0030] The respective leading end of each scraping member may be shaped to allow the scraping member to break a rock, and preferably tapers away from the frame e.g. is pointed.

[0031] The invention further extends to an excavator assembly which includes an excavator, a hydraulic hammer which is connected to an excavator arm, which has an impact member, which extends through an impact axis and which is operable by activation of the excavator arm to break rocks, and a scraper assembly of the aforementioned kind which is attached to the hydraulic hammer for scraping broken rocks and which is optionally configured to hold a rock in place to allow the hydraulic hammer to break the rock.

[0032] The excavator arm may be operable to move the hydraulic hammer thereby to allow the scraping members and the impact member to scrape or push broken rocks away from an area.

[0033] The support elements may extend from respective locations on the hydraulic hammer.

[0034] Each scraper element is preferably elongate and parallel to the impact axis.

[0035] Each scraping member may be movable between the respective aforementioned rest position, at which the scraping member is at rest, and the respective aforementioned limiting position.

[0036] The rest positions are preferably spaced apart from each other and are located on a scraper plane which extends perpendicularly through the impact axis.

[0037] An end of the impact member may be at a location on the impact axis which is closer to the hydraulic hammer than a point at which the scraper plane intersects the impact axis.

[0038] In use the respective leading end of each scraping member is brought into contact with a rock, such that each leading end is positioned between the respective rest position and therespective limiting position with the respective biasing element urging each scraping member towards the respective rest position thereby to inhibit movement of the rock and so facilitate breaking of the rock by the impact member.

[0039] The respective leading end of each scraping member may be shaped to allow the scraping member to break a rock in response to operation of the hydraulic hammer. Thus when the scraping members are correctly positioned relative to a rock, and as the hydraulic hammer is used to break the rock, a force is created by the hydraulic hammer which propagates through the scraper assembly i.e. through the frame and then to each scraper element thereby to cause a rock penetrating movement of each scraping member which movement assists in breaking the rock. The effect of this rock penetrating movement allows the scraper assembly to be used to produce a linear fracture in the broken rock thereby defining a straight trimmed edge or line in the broken rock, in accordance with the above mentioned orientation line.

[0040] An ultra-sonic sound generator may be mounted to the frame, which is operable by activation of the excavator arm, and which is configured to produce sound in a frequency which supplements the force created by the hydraulic hammer thereby to assist in breaking the rock. The frequency is preferably the same as the resonant frequency of the hydraulic hammer.

[0041] The invention also provides a method of using an excavator assembly of the aforementioned kind to break rocks at a site, and to remove broken rocks from the site, the method including the steps of operating the excavator arm to bring the impact member into contact with a rock, activating the excavator arm to operate the hydraulic hammer thereby to break the rock with the impact member, and operating the excavator arm to move the hydraulichammer to scrape broken rocks from the site with the scraping members and the impact member.

[0042] Prior to breaking the rock, the leading end of each scraping member is preferably brought into contact with the rock thereby to cause each leading end to be moved to a location between the respective rest position and the respective limiting position with the respective biasing element urging each scraping member towards the respective rest position such that the scraping members follow a shape of the rock and thereby inhibit movement of the rock.

[0043] To improve the efficiency of the hydraulic hammer, the scraping members may be positioned relative to the rock so that each leading end is brought into contact with the rock, the hydraulic hammer is then operated thereby to cause a force which is created by the hydraulic hammer to propagate through the scraper assembly to cause a rock penetrating movement at each scraping member, and then using said movement to break the rock.BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The invention is further described by way of example with reference to the accompanying drawings in which:Figure 1 illustrates in perspective a scraper assembly according to the invention;Figure 2 is a perspective view of an excavator assembly which includes a hydraulic hammer to which the scraper assembly shown in Figure 1 is attached;Figure 3 illustrates in perspective and on an enlarged scale a portion of the excavator assembly which is encircled in a broken line marked “A” in Figure 2;Figure 4 shows the hydraulic hammer and the scraper assembly of Figure 2 from the front and in more detail;Figure 5 is a side view of the hydraulic hammer and the scraper assembly shown in Figure 4;Figure 6 shows the hydraulic hammer and the scraper assembly shown in Figure 4 from the front, and in operation;Figure 7 shows, from the front, a scraper assembly which is mounted to a hydraulic hammer according to another form of the invention;Figure 8 is a plan view of the scraper assembly shown in Figure 7; andFigure 9 and Figure 10 respectively show, from the side, the scraper assembly of Figure 7 with a scraper element in a first position, and with the scraper element in a second position.DESCRIPTION OF PREFERRED EMBODIMENTS

[0045] Figure 1 of the accompanying drawings illustrates in perspective a scraper assembly 10 according to the invention.

[0046] The scraper assembly 10 includes a frame 12 which is attachable to a hydraulic hammer 14, shown in Figure 2, and a plurality of spaced apart scraper elements 16 which are mounted to the frame 12.

[0047] Each scraper element 16 comprises a respective biasing element 18 and a respective scraping member 20. The scraping member 20 has a leading end 22 and a trailing end 24.

[0048] Each biasing element 18 comprises a respective spring e.g. a helical metal coil with a predetermined spring coefficient. The biasing element 18 has a first end 26 which is securedto a location on the scraping member 20, and a second end 26A, and defines a volume 28 through which the scraping member 20 extends.

[0049] The frame 12 comprises a first support element 30 and a second support element 32. The first support element 30 has a first section 34 which is attachable, e.g. through the use of bolts or by welding, to a location on an outer surface of the hydraulic hammer 14, not shown, and a second section 36. The second section 36 extends at a right angle from the first section 34. A plurality of apertures 38 are formed at spaced apart locations on the second section 36.

[0050] The scraping members 20 extend through the respective apertures 38. The first support element 30 and the second support element 32 are spaced apart and oppose each other. The respective first end 26 and the respective second end 28 of each biasing element 18 abut portions of outer surfaces 40, 42 of the support elements 30, 32 which face each other. The biasing elements 18 are thus located between the support elements 30, 32.

[0051] The respective leading end 22 of each scraping member 20 tapers away from the frame 12 to form a point. The scraping members 20 are made from a suitable steel alloy which is corrosion resistant, wear resistant, and of a predetermined hardness and strength.

[0052] Figure 2 is a perspective view of an excavator assembly 50 which includes an excavator 52 with an excavator arm 54. A hydraulic hammer 14 is connected to the excavator arm 52 in a conventional manner, and an impact member 58, e.g. a chisel, extends from one end of the hydraulic hammer 14. An impact axis 60 is defined by the impact member 58. The hydraulic hammer 14 together with the impact member 58 is operable by activation of the excavator arm 54 to break rocks in a manner which is known in the art. A scraper assembly 10 as described hereinabove is attached to the hydraulic hammer 14 on a first side thereof so thatthe elongate scraper elements 16 are parallel to the impact axis 60. A scraper assembly 10A which is identical to the scraper assembly 10 except that it has been inverted about the impact axis 60 is attached to a second side which is opposite to the first side of the hydraulic hammer 14. The first section 34 of the first support element 30 is secured by means of bolts to a location on the first side of the hydraulic hammer with the second section 36 extending perpendicularly from the location. The second support element 32 is secured in a similar manner to another location on the first side of the hydraulic hammer. The scraper assembles 10, 10A are configured to hold a rock in place to allow the hydraulic hammer 14 to break the rock, and are configured to scrape rocks which have been broken by the hydraulic hammer 14 away from a work site.

[0053] Figure 3 is a perspective view on an enlarged scale of a portion of the excavator assembly 50 which is encircled in a broken line marked “A” in Figure 2. Figure 4 and Figure 5 are front and side views of the scraper assemblies 10, 10A which are attached to the hydraulic hammer 14, respectively.

[0054] Each scraping member 20 is movable between a rest position 62, at which the resultant force acting on the scraping member 20 is zero, and a limiting position 64. The direction of movement is parallel to the impact axis 60. The biasing elements 18 are configured to urge the scraping members 20 in a first direction 66 away from the support elements 30, 32 towards the rest positions 62 in response to a force acting on the scraping members 20 in a second direction 68 which is opposite to the first direction 66 towards the limiting positions 64.

[0055] The rest positions 62 are spaced apart from one another and are located on a scraper plane 70 which extends perpendicularly through the impact axis 60. Thus when the hydraulichammer 14 is positioned upright relative to the ground and the resultant forces acting on the scraping members 20 are zero, the scraping members 20 are at the same height above the ground.

[0056] An end of the impact member 58 is at a location on the impact axis 60 which is closer to the hydraulic hammer 14 than a point at which the scraper plane 70 intersects the scraper axis 60, i.e. when the hydraulic hammer 14 is positioned upright relative to the ground and the resultant forces acting on the scraping members 20 are zero, then the scraping members 20 are closer to the ground than the impact member 58.

[0057] Figure 6 shows the hydraulic hammer 14 and the scraper assemblies 10, 10A from the front, and in operation. The excavator arm 54 is operated by a user, not shown, to bring the respective leading end 22 of each scraping member 20 into contact with a rock. The excavator arm 54 is moved until the impact member 58 is brought into contact with the rock. As the rock exerts a respective force on each scraping member 20, the leading ends 22 are moved to respective locations between the rest positions 62 and the limiting positions 64 such that the scraping members 20 follow a shape of the rock. The biasing elements 18 urge the scraping members 20 towards the respective rest positions 62 thereby to inhibit movement of the rock. The excavator arm 54 is activated to operate the hydraulic hammer 14 thereby to break the rock with the impact member 58.

[0058] As the hydraulic hammer 14 is operated, a force created by the hydraulic hammer 14 is propagated through the frame 12 to the scraper elements 16 thereby to cause a rock penetrating movement of each scraping member 20. Since the respective leading ends 22 of the scraping members 20 taper away from the frame 12 to form points, said movement of thescraping members assists in breaking the rock. Once the rock has been broken into sufficiently small pieces, the excavator arm 54 is operated to move the hydraulic hammer to and fro to scrape the broken rocks from the site with the scraping members 20 and the impact member 58.

[0059] One advantage of the use of the scraper assemblies 10, 10A as add-ons to form an excavator assembly 50 according to the invention, is that a rock can be held in place while the hydraulic hammer 14 is used to break the rock. The rock breaking process is also made more efficient as there are more contact points, i.e. the respective leading ends 22 of the scraping members 20, on the rock, which make use of the rock penetrating movement caused by the hydraulic hammer 14 to break the rock.

[0060] Once the rock has been broken into sufficiently small fragments, the excavator arm 54 can be operated to move the hydraulic hammer 14 to and fro to scrape the broken rocks from the site with the scraping members 20 and the impact member 58. This allows the user to spend less time breaking and removing a rock of a predetermined size.

[0061] Figure 7 shows, from the front, a scraper assembly 100 which is mounted to a hydraulic hammer 102 according to a different form of the invention. Figure 8 is a plan view of the scraper assembly 100. The scraper assembly 100 includes a frame 104 which is attached to the hydraulic hammer 102 and a scraper element 106 which is mounted to the frame 104. The frame 104 comprises a first pair of guide members 108 and a second pair of guide members 110. The guide members, 108, 110, respectively oppose and are spaced apart from one another, and are configured to guide the scraper element 106 between a first position 112, shown in Figure 9, and a second position 114, shown in Figure 10.

[0062] A holding mechanism 116 is attached to the hydraulic hammer 102 and comprises a mechanical fastener which holds the scraper element 106 in the first position 112.

[0063] The scraper element 106 comprises a first metal plate 118, a second metal plate 120 which is spaced from and which opposes the first metal plate 118, and two bridging structures 122 which extend between respective ends 124, 126 of the metal plates 118, 120 such that a gap 128 is formed between the metal plates 118, 120, as shown in Figure 9. The guide members 108, 110 respectively project from sides of the hydraulic hammer 102 and are located within the gap 128.

[0064] The scraper assembly 100 is used, after the hydraulic hammer 102 has broken rocks, not shown, by operating the mechanical fastener 116 thereby to release the scraper element 106 which moves under gravitational action from the first position 112 to the second position 114. The direction of movement is parallel to an axis through which the hydraulic hammer extends i.e. an impact axis. The guide members 108 act as stoppers, and prevent the scraper element 106 from moving beyond the second position 114. The scraper element 106 is then used, by activating an excavator arm, not shown, to move the hydraulic hammer 102 to and fro, to scrape the broken rocks. The scraper element 106 is moved from the second position 114 to the first position 112 by activating the excavator arm to urge the lower end 126 of the scraper element 106 on a hard surface e.g. a rock. The guide members 110 prevent the scraper element 106 from moving past the first position 112, and the excavator arm is used to keep the scraper element 106 in place until the mechanical fastener 116 is actuated to hold the scraper element 106 in the first position 112. In an alternative approach the holding mechanism 116 comprises an electromagnetic assembly which is actuable to release or to hold the metal plates 118, 120 in position by generating or releasing an electromagnetic field.

[0065] An excavator assembly, not shown, which has a scraper assembly 100 mounted to a hydraulic hammer 102 of the excavator assembly, can be used to break rock into sufficiently small fragments, and thereafter to scrape the broken rocks with the scraper element 106 of the scraper assembly 100 from a site. Additionally, the scraper element 106 can be used to hold a rock in place for breaking by the hydraulic hammer 102. This provides the same advantages as described above for the scraper assemblies 10, 10A.

Claims

CLAIMS1. An excavator assembly which includes an excavator, a hydraulic hammer which is connected to an excavator arm, which has an impact member, which extends through an impact axis and which is operable by activation of the excavator arm to break rocks, and a scraper assembly for scraping broken rocks.

2. An excavator assembly according to claim 1 wherein the scraper assembly includes a frame which is attached to, or integrally formed with, a body of the hydraulic hammer and at least one scraper element which is mounted to the frame.

3. An excavator assembly according to claim 2 wherein the frame includes a pair of guide members which are opposed to and spaced apart from one another, for guiding the scraper element between a first position and a second position at which the scraper element can scrape broken rocks or hold a rock in place to allow the hydraulic hammer to break the rock.

4. An excavator assembly according to claim 3 wherein the scraper assembly includes a holding mechanism which is configured to hold the scraper element in the first position and which is operable to release the scraper element to allow the scraper element to move to the second position.

5. An excavator assembly according to claim 3 wherein the scraper element is moved between the first position and the second position by means of a hydraulic actuator, or under gravitational action.

6. An excavator assembly according to claim 2 wherein the scraper assembly includes a plurality of scraper elements which are releasably mounted to the frame at respective locations which are spaced apart from each other, on a straight orientation line or on a curved orientation line.

7. An excavator assembly according to claim 6 wherein each scraper element comprises a respective biasing element and a respective scraping member with a leading end and a trailing end.

8. An excavator assembly according to claim 7 wherein each biasing element comprises a respective helical metal coil spring which has a first end which is secured to a location on the scraping member and a second end, and which defines a volume through which the scraping member extends.

9. An excavator assembly according to claim 8 wherein the frame comprises first and second support elements which are attached to locations on an outer surface of the hydraulic hammer, in such a manner that the first support element and the second support element are spaced apart and oppose one another.

10. An excavator assembly according to claim 9 wherein each support element includes a respective plurality of spaced apart apertures through which the scraping members extend.

11. An excavator assembly according to claim 8 wherein the coils are located between the support elements and respective first ends and respective second ends of the coils abut portions of respective surfaces of the support elements which face each other.

12. An excavator assembly according to claim 11 wherein each scraping member is movable between a rest position at which the respective coil extends substantially along a length of a portion of the scraping member which is between the support elements and a limiting position at which the coil is fully compressed.

13. An excavator assembly according to claim 12 wherein each coil is configured to urge the respective scraping member in a first direction away from a support element towards the respective rest position in response to a force acting on the scraping member in a second direction which is opposite to the first direction towards the respective limiting position.

14. An excavator assembly according to claim 13 wherein the respective rest positions of the scraping members are spaced apart from each other and are located on a scraper plane which extends perpendicularly through the impact axis and an end of the impact member is at a location on the impact axis which is closer to the hydraulic hammer than a point at which the scraper plane intersects the impact axis.

15. An excavator assembly according to claim 14 wherein in use the respective leading end of each scraping member is brought into contact with a rock, such that each leading end is positioned between the respective rest position and the respective limiting position with the respective coil urging each scraping member towards the respective rest position thereby to inhibit movement of the rock and so facilitate breaking of the rock by the impact member.

16. An excavator assembly according to claim 14 wherein the respective leading end of each scraping member is shaped to allow the scraping member to break a rock in response to operation of the hydraulic hammer, whereby when the scraping members are correctlypositioned relative to a rock, and as the hydraulic hammer is used to break the rock, a force is created by the hydraulic hammer which propagates through the scraper assembly thereby to cause a rock penetrating movement of each scraping member which movement assists in breaking the rock, which allows the scraper assembly to be used to produce a linear fracture in the broken rock thereby to define a straight trimmed edge or line in the broken rock, in accordance with the orientation line.

17. An excavator assembly according to claim 6 wherein an ultra-sonic sound generator is mounted to the frame, which is operable by activation of the excavator arm, and which is configured to produce sound at a frequency which supplements the force created by the hydraulic hammer thereby to assist in breaking the rock.

18. A method of using an excavator assembly according to claim 7 to break rocks at a site, and to remove broken rocks from the site, the method including the steps of operating the excavator arm to bring the impact member into contact with a rock, activating the excavator arm to operate the hydraulic hammer thereby to break the rock with the impact member, and operating the excavator arm to move the hydraulic hammer to scrape broken rocks from the site with the scraping members and the impact member.

19. A method of using an excavator assembly according to claim 18 wherein, prior to breaking the rock, the leading end of each scraping member is brought into contact with the rock thereby to cause each leading end to be moved to a location between a respective rest position and a respective limiting position with a respective biasing element urging each scraping member towards the respective rest position such that the scraping members follow a shape of the rock thereby to inhibit movement of the rock.

20. A method of using an excavator assembly according to claim 18 wherein the scraping members are positioned relative to the rock so that each leading end is brought into contact with the rock, the hydraulic hammer is then operated thereby to cause a force which is created by the hydraulic hammer to propagate through the scraper assembly to cause a rock penetrating movement at each scraping member, and then using said movement to break the rock.

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