GB599388A - Improvements in machines for drilling polygonal holes - Google Patents

Abstract

599,388. Drilling-machines. TRIGGS, W. W. (Spindel-Motoren- & Maschinenfabrik Akt.-Ges.). May 2, 1945, No. 11145. [A Specification was laid open to inspection under Sect. 91 of the Acts, May 2, 1945.] [Class 83 (iii)] A device for drilling polygonal holes by means of a cutter having rotary movement around its longitudinal axis and planetary movement around an axis parallel thereto, has a tool spindle slidably supported in the eccentric bore of an adjustable eccentric sleeve which is driven to impart planetary movement to the tool,.the tool spindle being connected through an Oldham's coupling to a vertically adjustable spindle driven at selected speeds in timed relation and in the reverse direction to the eccentric sleeve, and the tool being supported at its lower end by a chuck-shaped guide carried by this sleeve. The device comprises a base 1, adapted to be mounted on the table of a drilling or like machine, carrying a stationary workholder 3 and a pair of vertical pillars 2, 2<1>. A head 6 is slidably adjustable on the pillars and supports the tool-driving gear. The tool 55 is carried in a socket chuck (see below) by a vertically adjustable head 53 which is connected for rotation and vertical movement with a spindle 31 through a dovetailed Oldham'stype coupling 54, 54<1>. Vertical'feed of this spindle is obtained through a hand-lever 39, rack-and-pinion gearing 36 and 37 and sleeve 32. A gear cluster 40 slidably keyed to the spindle and movable by a screw-operated fork, provides the drive to the spindle at different speeds, according to the number of sides of this polygon to be cut. More than two speeds may be provided for. The drive to these gears is obtained from a countershaft 28 driven by the main spindle 24 from the drilling &c. machine. This spindle carries a gear wheel 21 at its lower end which drives in a reverse direction a sleeve 9. The sleeve 9 is bored eccentrically to take a further sleeve 12, also bored eccentrically to take the tool-head 53. These sleeves are relatively adjustable so that the planetary motion of the cutter may be varied from zero to a maximum represented by the sum of the eccentricities of the sleeves. A supporting device 61 for the outer end of the tool is carried by the sleeve 12 with adjustable jaws, the toolcontacting ends of which may be provided with rollers or balls. Sockets.-The socket provided for gripping the tool comprises a sleeve 56 located in a tapered bore in the head 53 and having a number of balls 57 spaced around its periphery adapted to be wedged between the bore and the tool chamber by compression springs 58. The sleeve 56 contacts the member 60 at the lowermost position of the tool and automatically frees it for removal.