221,589. Shipley, A. H., and Berry, A. B. June 22, 1923. Drilling brush stocks.-An automatic machine is provided with a series of interchangeable units each comprising a head carrying a stock-holder and being adapted for mounting in the machine so that the head is capable of pivotal movement in a horizontal plane and the holder in a vertical plane. In the construction shown comprising a machine adapted to drill holes in one stock and set tufts in another, two units, each comprising a head 1 and a stocls-holder 2, are arranged on a slidable plate 3. Each head is provided with bosses 8, 9 the lower boss 9 being pivotally mounted in one of a number of recesses 10 in the plate 3. The upper boss fits in a bearing in an arm 14 carried by a post 11 the lower part of which is adjustably secured in a groove 12 in the plate 3. The heads are provided with arms 50 connected together by a link 51 which is formed with a groove 52 for engagement with a roller 53 carried by a bracket 54. The bracket is fixed to a slidably-mounted bar 55 adapted to be moved endwise to impart an oscillating movement to the units. The bar is connected by links 58 to one of a series of arms 59 on a shaft 60 which is oscillated by means comprising a lever 62, a link 63, a slide 64 with a series of holes in one of which is a detachable roll 67, and a pattern cam 66 engaging the roll. For each unit of the series there is a separate arm 59 and corresponding bearings 56 to receive the bar 55. The plate 3, for the purpose of moving the units towards or ' away from the tools, is reciprocated by means comprising an oscillating lever 15, a connecting rod 22, a spring 23 on the rod adapted to press against an apertured swivel-piece 26 carried by a lever 27, and a link 30 connecting the plate to the lever. The plate abuts a forward stop shortly before the movement of the rod 22 is completed and remains stationary while the tools operate on the brush stocks. Rearward movement of the plate is prevented by a spring-controlled detent 35 the end of which, as the plate moves against the forward stop, is adapted to spring behind the projection 36 on a plate 37 adjustably secured on the plate 3. The detent is tripped to release the plate 3 by means of a lever 42 the lower end of which is engaged by a stop 32 on the rod 22 shortly before the end of the forward movement of the plate, 3. The upper end of the lever is thereby moved forwardly against the action of a spring 45. On the reverse movement a roller 43 carried by the upper end of the lever 42 presses on a cam-face 44 on the detent forcing it out of engagement with the projection 36. Each of the stock-holders 2 is provided with pivot-pins 76 carrying swivel blocks 77 which work in horizontal slots in the sides of the head. A slide rod 79 passes axially through the bosses 8, 9 of each head and has mounted thereon a block 80 provided with trunnions carrying swivel blocks 82 which work in slots in a rearwardly-extending fork 84 formed on the stock-holder. Vertical movement of the rods causes the holders to oscillate on their pivots 76. The rods are supported on rollers 85 running in guides 86 formed on a yoke 87 which is secured to the upper end of a slidable post 88. The lower end of the post is engaged by an arm 92 of a bell-crank lever, the other arm 93 being connected by a link 94 to a slide 90. The slide has a series of holes in one of which is detachably secured a cam roll 95, adapted to be engaged by a pattern cam 91. Each holder is normally drawn backwardly by means comprising, on each side of the holder, a torsion spring 103 with one end fixed to a roller 102 connected by a chain 104 to the swivel block 77. A form-plate 99 on the holder is thus held in contact with an anvil comprising a bracket 105 attached to the plate 3 and carrying a nipple 106 with a ball 107. The holders may have at each side a series of holes so that the pivot-pins 76 may be inserted in different positions. The brush stock is clamped between a loose strip 109 on a ledge 108 and a pivoted jaw 110 carried by a nut slidable in a vertical groove and adapted to be actuated by a screw 113 rotatable in a bearing 114 on the holder.