US Patent: 2,125,584
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| Adjusting Device for Machine Tools
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Patentee:
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| Erich Rotzoli (exact or similar names) - Berlin-Frohnaw, Germany |
| Manufacturer: |
| Not known to have been produced |
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Patent Dates:
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| Applied: |
Nov. 15, 1937 |
| Granted: |
Aug. 02, 1938 |
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Joel Havens
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Description: |
| Application in Germany, 16 Nov 1936.
This Invention relates to a device for the automatic adjustment of errors in the pitch of screw spindle gears for the production of accurate longitudinal movements of machine guide blocks or sliding carriages, particularly in machine tools for the production of threads, as in screw threading lathes, thread grinding machines and the like. It is customary to overcome the error of pitch of the screw spindle of such machine tools by means of a curved bar which is shaped to correspond to the errors of the spindle and which is called a correction guide. This Correction guide is mounted upon the base of the machine parallel to channel guides or upon the moving guide block. A lever is mounted against the course of the curve of the correction guide which operates, to twist the thread bolt of the moving screw spindle. In this manner, greater or lesser supplementary movement is transmitted to the screw spindle and through it to the guide block or sliding carriage, which supplementary movement overcomes the error of pitch and assures an accurate even feeding motion of the guide block. In coordinating drilling and measuring machines which are provided with a manually operated measuring screw spindle with pitch drum and slide rule for the accurate shifting of the measuring guide block or sliding carriage, the nonius or the pitch drum is adjustingly twisted from the correction guide by means of a lever arrangement in order, to correct its helicoidal error. This well known coordinating arrangement functions with sufficient accuracy, however, only for a short period, after which deviations appear in the accurate feeding motion of the guide block or sliding carriage which are caused by the wear and tear of the guide screw spindle and of the guide block tracks, so that it becomes necessary to readjust the corrector guide. This is a painstaking and expensive procedure. An object of the invention is, to eliminate these disadvantages by providing an adjusting device which is, to a great extent, not affected by the wear and tear of the machine parts and which, over a period of tune, is more accurate. A further object consists in the mounting of a non-propelling prime or master thread spindle parallel to the screw spindle, which latter drives and feeds the guide block, said master spindle being driven in such manner that its threads or twistings appear to be stationary, as compared with the guide block movement, and which master spindle guides by means of its thread or twisting, at least one light ray which lies in moving relation to it, in such manner that one or the other of two photo cells is affected to activate an electro-magnetic device, which latter transmits an error correcting supplementary movement to the driving spindle in a known manner.
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