DRAWING
Further advantages result from the description of the drawing, below. An exemplary embodiment of the present invention is shown in the drawing. The drawing, the description and the claims contain numerous features in combination. One skilled in the art will also advantageously consider the features individually and combine them to form further reasonable combinations.
FIG. 1 shows an assembly shell, an oscillating plate, and internal components of an eccentric grinder installed in the assembly shell, with the connecting units which connect the assembly shell with the oscillating plate,
FIG. 2 shows a cover shell of the eccentric grinder, as viewed from the inside.
FIG. 3 shows a connecting unit with a receiving part, and oscillating elements inserted in the receiving part and in the oscillating plate,
FIG. 4 shows a detailed view of FIG. 1 with the connecting unit inserted in the assembly shell and in the oscillating plate, and
FIG. 5 shows the side of the receiving part which faces the oscillating plate.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
FIG. 1 shows a schematic depiction of an eccentric grinder with a cover shell in place; the cover shell is shown separately in FIG. 2. The eccentric grinder includes a housing element 10 of a housing 12 designed as an assembly shell, an electric motor 14, and an output shaft 16 which is driven by electric motor 14 and which is installed in housing element 10, and a plate-shaped oscillating body 18 with an oscillating plate 20 which is provided for grinding surfaces. Oscillating body 18 is connected with housing element 10 by connecting means 22 which include two separate connecting units 24. Each connecting unit 24 includes a receiving part 26 and two oscillating elements 28 designed as oscillating legs, each of which has a hexagonal cross section. Oscillating body 18 includes oscillating element receptacles 30 into which oscillating elements 28 are inserted, in the installed state of the eccentric grinder.
Housing element 10 is designed with pocket-like cavities 32, into which receiving parts 26 of connecting units 24 are inserted. Two projections 34, each of which forms a tongue-and-groove connection with receiving part 26, are mounted on the edge of each pocket-like cavity 32. In addition, housing element 10 includes several fastening means receptacles which are provided to receive fastening means 38 shown in FIG. 2.
FIG. 2 shows a housing element 40 designed as a cover shell. It includes several fastening means receptacles 42 which are designed as raised areas or, when viewed from the outside, as recesses, into which fastening means 38 are inserted from the outside. Fastening means receptacles 42 are located in the cover shell such that, when housing 12 is closed, each fastening means receptacle 42 is located opposite to one of the fastening means receptacles 36 of the assembly shell or housing element 10, and fastening means 38, e.g., screws, can be inserted into fastening means receptacles 36. Housing element 40 also includes pocket-like cavities 44 which, in the installed state of the eccentric grinder, are located opposite to pocket-like cavities 32 in housing element 10, and into which receiving parts 26 are inserted, in the installed state of the eccentric grinder. Two projections 46, each of which forms a tongue-and-groove connection with receiving part 26, are formed on the edge of each pocket-like cavity 44.
During operation of the eccentric grinder, oscillating body 18 is driven by a not-shown eccentric which is fastened to output shaft 16. The eccentric makes circular motions which are transferred to oscillating body 18. Oscillating elements 28 prevent oscillating body 18 from rotating relative to housing 12 and fix oscillating body 18 in position on housing 12, to prevent it from tilting relative to housing 12. Oscillating elements 28 are made of a material which is provided in order to deform elastically, e.g., rubber, and to permit oscillating body 18 to perform the swinging motion relative to housing 12 as induced by the eccentric.
When the eccentric grinder is assembled, the internal components, e.g., electric motor 14 and output shaft 16, are first installed in housing element 10. Receiving parts 26 are then inserted into pocket-like cavities 32 of housing element 10. An advantage of dividing connecting means 22 into separate connecting units 24 is that connecting means 22 can then also be easily installed in housing element 10 after output shaft 16 has been installed. Housing element 40 is then placed on housing element 10, so that receiving parts 26 can be inserted into pocket-like cavities 44 of housing element 40. Housing element 40 is then fastened to housing element 10 using fastening means 38, e.g., screws, and housing 12 of eccentric grinder is therefore closed.
Each of the oscillating elements 28 is now inserted into one of the receiving parts 26. Oscillating elements 28 are then inserted into oscillating element receptacles 30 of oscillating body 18 by pressing lightly on oscillating body 18 relative to housing 12. Finally, oscillating body 18 is fastened to the eccentric using a screw. Receiving parts 26 are connected non-positively with both housing elements 10, 40 and with all oscillating elements 28. As a result, these parts can be installed easily, reliably, and correctly.
When maintenance or major repair work is performed on the eccentric grinder, e.g., to repair or replace defective components in the eccentric grinder, housing element 40—which is designed as a cover shell—must be removed in order to access the internal components. To do this, the eccentric grinder does not have to be disassembled in the reverse order of its assembly. Instead, it is only necessary to release fastening means 38 and lift the cover shell away from housing element 10, which is designed as an assembly shell. The cover shell can be lifted off of receiving parts 26, which remain in the assembly shell along with the oscillating elements 28, oscillating body 18, and the fastening to the eccentric.
To replace oscillating elements 28, the fastening of oscillating body 18 on the eccentric is released, and oscillating elements 28 are separated from oscillating element receptacles 30 in oscillating body 18 by pulling lightly on oscillating body 18. Oscillating elements 28 can then be pulled out of receiving parts 26 without having to disassemble housing element 40.
FIG. 3 shows connecting unit 24 with the two oscillating elements 28 which, in the installed state of the eccentric grinder, are each inserted into one of the oscillating element receptacles 30 of oscillating body 18. When round oscillating elements 28 are used, rotation of oscillating elements 28 during operation of the eccentric grinder in the receiving part 26 and in oscillating element receptacle 30 can cause undesired wear, e.g., on oscillating elements 28. By selecting a polygonal geometry of oscillating elements 28, which are hexagonal in design, it can be attained that this wear is reduced considerably, which increases the service life of oscillating elements 28. Receiving part 26 also has a groove 48, which is located parallel to oscillating plate 20.
In FIG. 4, connecting unit 24 is shown installed in housing element 10. Receiving part 26 is inserted into pocket-like cavity 32 of housing element 10. Via groove 48 of receiving part 26 and projections 34 and 46, receiving part 26 and housing element 10 and 40 are connected by a tongue-and-groove connection, in the installed state of the eccentric grinder. This contributes to a particularly stable fastening and exact positioning of receiving part 26 on both housing elements 10, 40, and enables quick assembly and disassembly. An alternative oscillating element 28a is also shown. It is hexagonal in design only in its outer regions, and has a round cross section in a central region. To make it easier to press oscillating element 28a into oscillating body 18, a ventilation hole 49 is provided in the oscillating body.
FIG. 5 shows the side of receiving part 26 which faces oscillating body 18. Receiving part 26 includes receiving means 50 which include two recesses 52. Recesses 52 are provided to accommodate one oscillating element 28 each, and are therefore designed to match the hexagonal geometry of oscillating elements 28. During assembly, oscillating elements 28 are inserted into recesses 52, which also enables assembly to be carried out in an efficient manner.
Patent Application
20080070487
