Patent GB-329272-A (GB)
Title: Improvements in or relating to combined drilling and tapping machines
IPC: B23B39/16
Filed: 1929-02-11
Abstract: 329,272. Heide, H. C., (National Automatic Tool Co.). Feb,. 11, 1929. Drilling-machines; tapping.-A combined drilling and tapping machine has a unidirectional drive for the drill-spindle, a reversing drive for the tap-spindle, means for feeding the tap spindle and means actuated or controlled by the reverse movements of the tap-spindle drive for feeding the drill-spindle. In one form the machine comprises a column D, Figs. 1 and 2 supported on a base A and carrying an interchangeable head E having drill - spindles a - - d and tapping spindles e - - h. A shaft 7 rotated through bevel gearing 5 from an electric motor M rotates the drill spindles directly through the gearing 11 - - 21, Fig. 2, and also carries a worm engaging a worm wheel 23, Fig. 1 which rotates a shaft 25 through a clutch 28. A bevel pinion 29 on the shaft 25 drives a bevel gear 30 keyed to a shaft 33 carrying a crank 35 whose roller-pin 36 engages a slot 37 in a segmental gear 38, pivoted at 40 and having teeth meshing with a pinion 42 on a shaft 43 to rotate the shaft and the tap-spindles alternately m opposite directions. The shaft 43 drives the tap-spindles through gearing 44-57, the gears 15, 19 of the drill-train and 51, 55 of the taptrain being elongated so as to allow the spindle pinions engaging therewith to have axial feeding movement. The tap spindles are fed and withdrawn by lead-screws 59 thereon rotating in feed-nuts 60 attached to the drill head and the rotation and feed of the spindles is stopped after one advance and retraction by means of an arm on the boss of the segmental gear 38 carrying a spring 90 which acts on an arm 87 on a clutch operating rod 76. The rod is rotatable but axially immovable in a yoke 80 connected to the clutch 28 and the rod is normally pressed to the right in Fig. 1 by means of a spring (not shown). To start a cycle of operations the rod is rotated against the torsion of the spring by a hand lever 77 to disengage the arm 87 from the spring 90 and is then moved axially to connect the clutch 28. The drill-spindles are fed by means of ball thrust collars thereon in contact with a common plate 62 which is normally held up by springs 63 but is depressed for feeding by a lever 68. The lever is secured to a shaft 64, Figs. 1 and 2 provided with a second lever 69 which is oscillated by a roller 70 thereon resting on the wedge-shaped upper surface 71 of a bar 72. Rack teeth 73 on one side of the bar are in mesh with a pinion 75 on the upper end of the tap-rotating shaft 43, driven alternately in opposite directions by the segmental gear 38. The head E may be changed for one having a different disposition of drill and tap spindles to suit the requirements of other work, the initial gears 11, 44 of the drill and tap rotating trains respectively; occupying the same position in each head so that they may be slid on to the upper ends of the driving shafts 7. 43. The work may be passed from the drills to the taps by means of a rotatable work-table, indexed by hand or power, or by other means. The gearing is lubricated by a gear pump, L, Fig. 1 located in a sump of the casing B and driven by a pinion 91 on the shaft 7. The pump delivers by a pipe 93 to the top casing G whence lubricant proceeds by an overflow pipe 94 to the casing F and thence by an overflow pipe 95 through the column D to the sump. In a modified machine, which may be either a drilling or a tapping machine (although both drills and taps are shown for convenience in Figs. 10 and 12), the driving motor M drives a pulley 101 connected by a belt 102 passing over jockey pulleys 109 to a pulley 107 on a shalt 108. When drillspindles i, j, k, are used they are rotated by gears 112-118, Fig. 12 from a pinion 111 on the shaft 108, the gears 114, 117 being elongated to permit axial feed of the spindles, For tapping, the drill-spindles are released from the pinions 115, 116, 118 and are replaced by tap-spindles and the belt 102 is replaced by a belt 119, Fig. 10 transmitting motion from the pulley 101 to a pulley 120, on a shaft 121 carrying a worm 125, Fig. 11. The worm drives, through a wheel 126 on a shaft 127, a crank 128 having a roller-pin 129 engaging a slot 130 in a segmental gear 131, journaled on a shaft 133 and meshing with a pinion 135 on a shaft 136 having a pinion 139 thereon engaging a gear 140 splined to a shaft 141. For drilling the gear 140 is moved by a yoke 145 out of engagement with the pinion 139, but for tapping transmits the alternate forward and reverse rotation to a pinion 146 which drives the tap-spindles i, j, k through the gear train 147, 116, 114, 117, 115 and 118. The tap spindles are fed by screwed extensions 148 thereon and stationary lead nuts 149, and the drill spindles are fed by an arcuate cam 150, Fig. 10 on the underside of the segmental gear 131 engaging a roller 151 on an arm 152 secured to a shaft 153 which rocks a shaft 157 through another arm and a connecting rod 155. The shaft 157 carries three arms 158<a> whose outer ends depress the spindles through ball thrust bearings 159 against the pressure of springs 161. - A bearing rib 162 on the upper surface of the segmental gear co-acts with the machine frame to take the thrust of the cam 150. To render the feed inactive, the shaft 153 may be disconnected from the connecting rod 155. In a further modified machine having combinations of tapping and drilling spindles, the spindle i, Fig. 14, is driven by gears 202, 201, 200 and the spindles j, k by gears 206 - - 209. When all the spindles are for drilling, the gear 200 is rotated from a pinion 111 on the shaft 108 of a belt pulley 107, Fig. 13, and the gear 206 is rotated by a pinion 205 on a shaft 141 connected by gears 203, 204 and a clutch 211 to the shaft 108. When all the spindles are for tapping the gear 200 is clutched to the gear 205 and the gear 203 is clutched to a shaft 136 carrying the pinion 135 rotated alternately in opposite directions by the segmental gear 131. The spindle i may be driven unidirectionally for drilling and the spindles j, k reversely for tapping by moving the gear 200 upwardly and the gear 203 downwardly. Turrets.-To enable holes to be drilled in closer proximity than the drill-spindles, the work may be carried by a table T rotatably indexable to present the work to each spindle in turn. A Geneva wheel 164, Figs. 10 and 11, is intermittently rotated on the shaft 133 by a roller 165 on the worm-wheel 126 and has secured thereto a gear 166 engaging a gear 167 attached to a stubshaft 168. Change gears 169, 170 are removably secured to the stub shaft 133 to which the table T is keyed. By altering the change wheels any desired angular movement may be imparted to the table, locking being effected by a segmental block 171 on the worm-wheel and arcuate notches 172 in the periphery of the Geneva wheel. Lubricating cutting-tools and work.-The bottom section A, Fig. 1 of the machine frame forms a compartment for cutting-compound which is delivered by a motor driven pump P, a discharge pipe 2 and nozzles 3 to the tools.