TOOL OF A BREAKING APPARATUS

Abstract: The invention relates to a tool of a breaking apparatus, such as a percussion hammer or percussion drill, especially for improving the lubrication of the tool. According to the invention, grooves (4, 5, 7) circling at least in one direction when the tool is rotated around the vertical axis (3) are formed on the outer surface of the tool (1) of the breaking apparatus, near the tool end (2, 8) to be attached to the breaking apparatus.

Description: Tool of a breaking apparatus The invention relates to a tool of a breaking apparatus, such as a percussion hammer or percussion drill, especially for improving the lubrication of the tool. A conventional breaking apparatus utilizes separate tools attached to the breaking apparatus and having a substantially smooth surface at the end to be fastened to the breaking apparatus. A tool is usually attached to a breaking apparatus by means of a sleeve placed in the breaking apparatus. In order to work advantageously, such a sleeve joint of the tool requires lubrication between the sleeve and the tool of the breaking apparatus. In order to provide the lubrication between the tool and the sleeve, the latter is at least partly grooved on the surface touching the tool, whereupon it is possible to substantially decrease the running of the lubricant away from the surfaces to be lubricated during the use of the breaking apparatus, and to spread the lubricant more evenly between the different parts of the joint surfaces. The purpose of the present invention is to eliminate prior art drawbacks and to provide an improved tool of a breaking apparatus which is easier to use and by means of which the lubrication of the joint between the breaking apparatus and the tool is ameliorated. The essential characteristics of the invention are disclosed in the appended claims. According to the invention, a grooving is formed on the outer surface of the tool of the breaking apparatus, near the tool end to be attached to the breaking apparatus, in order to advantageously lubricate the joint surfaces between the tool and the breaking apparatus. The grooving is formed of grooves circling the outer surface of the tool in at least one direction, and the grooves circling the outer surface of the tool in the same direction during the rotation of the tool with respect to the vertical axis are preferably situated at substantially equal intervals from one another. According to the invention, the grooves formed in the tool of the breaking apparatus circle the outer surface of the tool in such a way that the angle of elevation measured from the horizontal plane is between 0 and 45 degrees, preferably between 10 and 25 degrees. The grooving formed in the tool consists of grooves that are preferably placed crosswise with respect to each other and that circle the outer surface of the tool in different directions in such a way that grooves running parallel during the rotation of the tool around the vertical axis are situated at substantially equal intervals from one another. The grooves formed in the tool may also be mutually parallel, whereupon the angle of elevation is 0 degrees. When the angle of elevation of the grooves formed in the tool of the breaking apparatus is more than 0 degrees, the grooves are preferably made to begin at substantially equal intervals from one another from the tool end to be attached to the breaking apparatus. The accuracy of the mutual positioning of the grooves in the tool can be advantageously improved in such a way that grooves that circle the tool in opposite directions during the rotation of the tool around the vertical axis are made to begin from substantially the same point situated on the edge of the tool end to be attached to the breaking apparatus. According to the invention, the grooves formed in the tool of the breaking apparatus preferably cover the tool over a distance the length of which is 0.5 to 2 times the diameter, calculated from the tool end to be attached to the breaking apparatus, when this end is substantially circular. When the tool end to be attached to the breaking apparatus substantially differs from circular, i.e. it has for example the shape of a polygon, the grooves formed in the tool cover the tool over a distance the length of which is 0.5 to 2 times the longest interval running through the centre of the tool end to be attached to the breaking apparatus between two points situated on the perimeter of the same tool end, the distance being calculated also from the same tool end. However, the grooves formed on the outer surface of the tool of the breaking apparatus according to the invention and beginning from the tool end to be attached to the breaking apparatus preferably cover only the part entering the breaking apparatus when the tool is being attached thereto. By forming the grooving according to the invention on the outer surface of the tool of the breaking apparatus substantially near the end to be attached to the breaking apparatus, the lubricant for the joint surfaces between the tool and the breaking apparatus can be preferably supplied in such a way that the lubricant is spread substantially evenly onto the grooving of the tool. The lubricant is then also made to spread substantially evenly onto the corresponding joint surface of the breaking apparatus. Furthermore, by means of the invention it is possible to reduce the costs of manufacturing the joint between the breaking apparatus and the tool, since it is easier to form a grooving on the outer surface of the tool than on the inner surface of the connecting piece of the breaking apparatus. In the following, the invention will be described in greater detail with reference to the accompanying drawing, in which Figure 1 shows a preferred embodiment of the invention, Figure 2 shows a second preferred embodiment of the invention, Figure 3 shows a third preferred embodiment of the invention. According to Figure 1, the tool 1 of the breaking apparatus comprises grooves 4 and 5 circling the tool 1 in different directions of rotation, clockwise and counterclockwise, with respect to the vertical axis 3 of the tool, the grooves being formed to begin from the tool end 2 to be attached to the breaking apparatus. The grooves 4 circling clockwise and correspondingly the grooves 5 circling counterclockwise are mutually substantially parallel, and the angle of elevation is 15 degrees. The grooves 4 and 5 are made to begin preferably in pairs in such a way that both the groove 4 circling clockwise and the groove 5 circling counterclockwise with respect to the vertical axis 3 of the tool are made to begin from substantially the same point 6 situated on the perimeter of the tool end 2 to be attached to the breaking apparatus. In Figure 2, substantially mutually parallel grooves 7 that are preferably situated at equal intervals from one another are formed on the outer surface of the tool 1 substantially near the tool end 2 to be attached to the breaking apparatus. The embodiment of Figure 3 differs from the embodiment of Figure 2 in that the mutually parallel grooves 7 are formed around the end 8 of the tool 1 to be attached to the breaking apparatus, the end having a cross-section that substantially differs from circular.

Claims: Claims 1. A tool of a breaking apparatus, such as a percussion hammer or percussion drill, c h a r a c¬ t e r i z e d in that grooves (4,5,7) circling at least in one direction when the tool is rotated around the vertical axis (3) are formed on the outer surface of the tool (1) of the breaking apparatus, near the tool end (2,8) to be attached to the breaking apparatus. 2. A tool of a breaking apparatus according to claim 1, c h a r a c t e r i z e d in that the grooves (4,5,7) formed in the tool circle the tool (1) with the angle of elevation being between 0 and 45 degrees, preferably 10 to 25 degrees, with respect to the horizontal plane. 3. A tool of a breaking apparatus according to claim 1 or 2, c h a r a c t e r i z e d in that the grooves (4,5,7) circling the outer surface of the tool in the same direction when the tool (1) is rotated around the vertical axis (3) are preferably situated at substantially equal intervals from one another. 4. A tool of a breaking apparatus according to claim 1, 2 or 3, c h a r a c t e r i z e d in that the tool (1) comprises grooves (4,5) formed in a crosswise position and circling the outer surface of the tool in different directions so that grooves running parallel during the rotation of the tool (1) around the vertical axis (3) are situated at substantially equal intervals from one another. 5. A tool of a breaking apparatus according to claim 4, c h a r a c t e r i z e d in that grooves (4,5) circling in opposite directions when the tool is rotated around the vertical axis (3) are made to begin from substantially the same point (6) situated on the edge of the tool end (2) to be attached to the breaking apparatus. 6. A tool of a breaking apparatus according to any one of the preceding claims, c h a r a c t e r- i z e d in that grooves (4) are formed on the outer surface of the tool (1) over a distance the length of which is 0.5 to 2 times the diameter of the tool end (2) to be attached to the breaking apparatus. 7. A tool of a breaking apparatus according to any one of claims 1 to 5, c h a r a c t e r i z e d in that grooves (4) are formed on the outer surface of the tool (1) over a distance the length of which is 0.5 to 2 times the longest interval between two points situated on the perimeter of the tool end (8) to be attached to the breaking apparatus, the interval running through the centre of said tool end (8) to be attached to the breaking apparatus.

Inventors: JUURI KAUKO, SALO JOUNI, JUURI, KAUKO, SALO, JOUNI
Applicants: BRETEC OY, JUURI KAUKO, SALO JOUNI, JUURI, KAUKO, SALO, JOUNI
Application year: 1995
Main classification: B25D17
IPC codes: B25D17