Views:4 Author:Site Editor Publish Time: 2017-02-14 Origin:Site
The Oscillating knife cutting machine was to create a cutting machine with an oscillating knife comprising a grinding device which need not be displaced manually, and being of a simpler design than the known cutting machine with an oscillating knife comprising a grinding device which is displaceable by a motor. Departing from a cutting machine of the first aforementioned kind this object is attained in accordance with the invention by the spindle being of cylindrical configuration in the region of the helical path and the second advancing member in the form of a friction wheel abutting the spindle, and furthermore by the friction wheel axis being inclined with respect to the spindle axis. Gearing which is known per se is used in the inventive cutting machine, however, this gearing was hitherto only used in relatively large machines with advancing lengths of approximately 2 meters and more. Use of this gearing principle in an apparatus such as a cutting machine with an oscillating knife, which is to be classified in the field of precision mechanics, was therefore not rendered obvious by the known gearings.
The Oscillating knife cutting machine not only has the advantage that no thread need be machined on the spindle, but, what is much more important, the inclination of the friction wheel axis with respect to the spindle wheel axis can be chosen almost as small as desired, without resulting functional disturbances, and consequently, the spindle can be driven at a high rotational speed without having the disadvantage of rapid reciprocation of the grinding device. Therefore, contrary to the known construction, the grinding element of the grinding device in the inventive cutting machine can also be driven at a high rotational speed.
The grinding device must, of course, not necessarily be guided in or at the motor housing--it is, for example, conceivable to guide the grinding device at the knife guide means extending along the knife, so that within the meaning of the definition of the invention the knife guide means is to be considered part of the housing. Grinding wheels and also endless grinding belts can be used as grinding elements.
In principle, there are two different ways of both lowering and raising the grinding device by a motor without reversing the direction of rotation of the spindle: In a preferred embodiment of the inventive cutting machine the friction wheel axis is pivotable between two positions in which it is inclined with respect to the spindle axis in opposite directions, so that the grinding device is lowered in one position of the friction wheel axis and raised in the other position. Two friction wheels with axes which are oppositely inclined with respect to the spindle axis could, however, also be provided and the two friction wheels made to abut the spindle alternately so as to lower the grinding device with one friction wheel and raise it with the other.