GB663964A - Improvements relating to machine tools - Google Patents

Abstract

663,964. Machine-tool details. SOC. GENEVOISE D'INSTRUMENTS DE PHYSIQUE. June 13, 1949 [June 16, 1948], No. 15699/49. Class 83 (iii). Gauging - devices.- In a machine-tool comprising at least one slide 2 having a precision rule 13 attached thereto which is observed by optical means, e.g. a micrometric microscope, a device is provided which enables the positions already occupied by the slide to be repeated, this device comprising a set of adjustable stops 17, 17<SP>1</SP>, 17<SP>11 </SP>co-operating with a position indicator which comprises a prismatic piece 22 provided at one end of a pivotally - mounted spring-influenced lever 23 having a member 28 which acts upon one end of a pusher member 29, the other end of which acts upon a member 37 fixed to an oscillatable frame 39 carrying a mirror 40 which reflects the light from a lamp bulb 43, containing a rectilinear filament 44, towards a fixed mirror 41 which in turn reflects the light on to a translucent screen 42 having a fixed pointer 50. The slide has a pointer 65 co-operating with a scale 66 provided on the machine frame. The movement of the slide is controlled either by means of a hand-wheel 7 acting through pinions or by means of a motor which drives a shaft 12. In operation, assuming the co-ordinate of a machining position to be 300.469 mms., the micrometer head 59 of the microscope is set to the reading 0.469 and the slide is moved mechanically until the pointer 65 comes into the immediate neighbourhood of the mark 300 mms. on the scale,66. The slide is then moved by means of the hand wheel 7 until the mark of the graduation on the rule 13 is coincident with the reticule in the field of the microscope eyepiece 64. At this moment, one of the stops 17 is moved until the conical point 21 of an adjusting screw 20 thereof engages the prismatic piece 22 of the position indicator. The stop is then fixed to the slide by means of a screw 18 and the screw 20 adjusted until the image 51 of the filament 44 coincides with the pointer 60 on the screen 42. The above operative steps are repeated for each of the other co-ordinates that have to be repeated. The slide is then returned to the co-ordinates marked previously merely by operating the mechanical and manual control devices thereof. The Specification as open to inspection under Sect. 91 comprises also a mechanical or electrical operating device which may be used instead of an optical position indicator. This subject-matter does not appear in the Specification as accepted.