Abstract: A multiple spindle bar machine (10) includes in its preferred embodiment three main spindles (66) that are opposed by three counterspindles (106) of substantially identical construction. The main spindles (66) can be indexed about the Z axis. The counterspindles (106) cannot be indexed, but they can translate along the Z-axis. Each main spindle (66) is hollow and contains a workpiece-grasping collet chuck (68). At least one of the counterspindles (106) contains a workpiece-grasping collet chuck (108). The main spindles (66) are rotated in unison, but the counterspindles (106) are rotated independently by computer-controlled motors. In the preferred embodiment, three tool-carrying turrets (20A, 20B, 20C) are radially spaced around the machine at three work stations. Preferably, the turrets (20A, 20B) located at the first and second workstations can be moved along both the X and Z axes, while the turret (20C) located at the third workstation can be moved along the X axis.

Abstract: A multiple spindle bar machine (10) includes in its preferred embodiment three main spindles (66) that are opposed by three counterspindles (106) of substantially identical construction. The main spindles (66) can be indexed about the Z axis. The counterspindles (106) cannot be indexed, but they can translate along the Z-axis. Each main spindle (66) is hollow and contains a workpiece-grasping collet chuck (68). At least one of the counterspindles (106) contains a workpiece-grasping collet chuck (108). The main spindles (66) are rotated in unison, but the counterspindles (106) are rotated independently by computer-controlled motors. In the preferred embodiment, three tool-carrying turrets (20A, 20B, 20C) are radially spaced around the machine at three work stations. Preferably, the turrets (20A, 20B) located at the first and second workstations can be moved along both the X and Z axes, while the turret (20C) located at the third workstation can be moved along the X axis.

Abstract: A multiple spindle bar machine is disclosed including a cylindrical spindle carrier assembly supporting a spaced apart array of spindle bearings. Workpiece holding spindles are rotatably journaled in the spindle bearings. A hollow spindle drive shaft extends through a central opening in the spindle carrier and includes a drive gear pinned to an end of the shaft. The drive gear intermeshes with spindle gears to drive the spindles at a uniform rotational speed. The spindle carrier assembly is rotatably supported by at least one set of tapered roller bearings bearing against an outer peripheral surface of a spindle carrier. The set of roller bearings are disposed in a notched annulus in an inner peripheral surface a headstock upright. Each roller bearing forms an acute included angle between the spindle carrier outer peripheral surface and a surface of the tapered bearing facing the spindle carrier. The set of tapered roller bearing is mechanically preloaded before machining operations commence.

Abstract: A bar stock feeder for feeding bar stock to a multiple spindle lathe is disclosed. The bar stock feeder has several guide tubes, each for holding a piece of stock. The tubes are flooded with hydraulic fluid to provide a film of fluid to support the pieces of stock. Each tube contains a piston for advancing the pieces of stock towards the lathe. The tubes have a pivoting part which allows the operator to separate the tubes for reloading. The pistons are retracted into the pivoting part of the tubes prior to separation such that they are not in the way during reloading.

Abstract: A multispindle lathe is disclosed which has an indexable drum including a plurality of main spindles. A secondary spindle opposes the main spindles so that it is coaxial with one of the main spindles at an indexed position. The secondary spindle is rotatable on a fixed axis and can be moved axially towards the main spindle. The rotation of the secondary spindle can be synchronized with the rotation of the main spindle so that both spindles can hold a workpiece. A cut off tool moves transversely to the spindles to cut the workpiece from bar stock which has been fed into the main spindle. After cut off, the secondary spindle moves away from the main spindle and a secondary tool moves transversely to the secondary spindle to machine the end of the workpiece which has just been cut off. Movement of the secondary tool and secondary spindle can be coordinated to form curves and tapered threads.