GB511431A - Improvements in and relating to work-locating devices for drilling, milling and likemachines - Google Patents

Abstract

511,431. Drilling ; mining. JAMESON, J. L. Feb. 14, 1938, No. 4586. [Class 83 (iii)] A locating device for setting the work in relation to the tool of a boring, milling &c. machine includes two electrical contacts which are adapted conjointly to control an indicator so that the indicator is actuated when the tool and work are in the required position, but one contact or the other is broken to interrupt the operation of the indicator when the relative position of the work to the tool is altered in one or the other direction. The device comprises a bracket 7 carried by a diametrical guide 6 on a circular frame 5 mounted concentrically with the axis of the tool spindle supported in a head 2. An arm 8 depending from the bracket 7 carries an electric contact 9 for engagement with the work 3 and a spring 11 maintains the bracket in engagement with an adjustable electric contact 10 on the frame 5, the adjustment being made so that the end of the contact 9 is exactly on the axis of the tool spindle. An electric circuit is formed as shown in Fig. 1, including the work, bracket 7, a battery 12 and a lamp or bell 13 so that as the work is fed towards the tool axis a reference surface 4 thereon will engage the contact 9 when it reaches the tool axis, thus completing the circuit and actuating the indicator 13, but if the work is moved past this point the bracket 7 will be displaced against the pressure of the spring 11 and the circuit will be broken at 10, thus de-energizing the indicator. The end of the contact 9 may be small so as to engage a selected part of the work only, and the circuit may be arranged so that the indicator is deenergized when the work reaches the required position. The bracket 7 may be pivoted instead of slidable. In order to effect an adjustment of the work in two directions at an angle to each other, the frame 5 is carried by a circular guide 15 on a sub-frame 16 attached to the tool head 2 and is secured in an angularly adjusted position by bolts 17 on the sub-frame passing through arcuate slots 18 in the frame 5. To allow access to the tool the sub-frame is pivoted at 17<1> to the tool head and is secured in operative position by a swinging bolt 18<1> engaging lugs on the head.