GB469206A - Chair corner bracket boring machine attachment - Google Patents

Abstract

469,206. Drilling-machines. KEARLEY, F. J. April 25, 1936, No. 11858. [Class 83 (iii)] In a horizontal or spindleturret drilling - machine detachable mechanism is provided for automatically positioning the work before a number of drills in succession so that a number of successive drilling operations may be performed. The attachment is particularly designed for drilling corner brackets or blocks such as are used in the manufacture of chairs &c. The brackets a are stacked in a vertical shoot 25, Figs. 2 and 3, and the lowermost bracket is normally held by a spring plunger 18 carried by a vertically adjustable arm 17. A hand lever 4 is pivoted at 4a above the table 1 which is removably attached to the machine, and carries a hook-shaped plate 6 which lies under the shoot. On rearward movement of the lever a dog 7 thereon engages a pin 20 on the plunger 18 to withdraw the latter and allow the lowermost bracket to fall on the plate 6, but when the lever is moved forwards again the bracket is prevented from moving by the forward edge of the shoot, and when the hook end of the plate 6 has passed, the bracket falls on a plate 27 and the plunger 18 is returned by its spring to hold the next bracket. A recessed part 4b on the lever 4 then engages the bracket to slide it forwards on the plate 27 and clamp it against an upturned edge 1b of the table 1 where the first hole may be drilled by a drill a<1>. The bracket is held vertically on the plate 27 by rollers 23 on a vertical slide 24 which is yieldingly mounted by means of a volute spring 22. When the lever 4 is rocked rearwardly the hook on the plate 6 slides the drilled bracket rearwardly on the plate 27 until it drops on a plate 33 carried by a lever 3 having a pivoted lost-motion connection 3a with the lever 4. A linkage 8, 10 pivoted to the lever 4 presses on the free end of the lever 3 to cause it to follow the motion of the lever 4 but slightly out of phase on account of the lost-motion pivot. On the next forward motion of the levers 3, 4, an undrilled bracket falls on the plate 27 and the partly drilled bracket is engaged by a recess 3b on the lever 3 to be clamped against a spring stop 28 on the table 1 in position for having the second hole drilled by a drill a<2>, the positioning of the bracket being assisted by a spring-loaded arm 12 having a notch at the end and mounted on a vertical pivot on the table 1. The recesses 3b, 4b in the levers 3, 4 are angularly related as shown in Fig. 4 to position the brackets at the required angle for each hole. On the next rearward movement of the levers 3, 4 a stop 11 on the table 1 passing through a slot in the lever 3 engages the completely drilled bracket to sweep it off the plate 33, and allow it to fall through a notch 1c in the table 1.