Taper attachments, like lathes, vary some in their construction, but all operate on the same principle. An improved form of taper attachment is illustrated in [Figs. 9] and [10]. [Fig. 9] shows a plan view of a lathe carriage with an attachment fitted to it, and [Fig. 10] a sectional view. This attachment has an arm A on which is mounted a slide S that can be turned about a central pivot by adjusting screw D. The arm A is supported by, and is free to slide on, a bracket B (see also sectional view) that is fastened to the carriage, and on one end of the arm there is a clamp C that is attached to the lathe bed when turning tapers. On the slide S there is a shoe F that is connected to bar E which passes beneath the toolslide. The rear end of the cross-feed screw is connected to this bar, and the latter is clamped to the toolslide when the attachment is in use.
Fig. 10. Sectional View of Taper Attachment
When a taper is to be turned, the carriage is moved opposite the taper part and clamp C is fastened to the bed; this holds arm A and slide S stationary so that the carriage, with bracket B and shoe F, can be moved with relation to the slide. If this slide S is set at an angle, as shown, the shoe as it moves along causes the toolslide and tool to move in or out, but if the slide is set parallel to the carriage travel, the toolslide remains stationary. Now if the tool, as it feeds lengthwise of the work, is also gradually moved crosswise, it will turn a taper, and as this crosswise movement is caused by the angularity of slide S, different tapers are obtained by setting the slide to different positions.
By means of a graduated scale G at the end of slide S, the taper that will be obtained for any angular position of the slide is shown. On some attachments there are two sets of graduations, one giving the taper in inches per foot and the other in degrees. While tapers are ordinarily given in inches per foot on drawings, sometimes the taper is given in degrees instead. The attachment is set for turning tapers by adjusting slide S until pointer p is opposite the division or fractional part of a division representing the taper. The whole divisions on the scale represent taper in inches per foot, and by means of the sub-divisions, the slide can be set for turning fractional parts of an inch per foot. When slide S is properly set, it is clamped to arm A by the nuts N. Bar E is also clamped to the toolslide by bolt H, as previously stated. The attachment is disconnected for straight turning by simply loosening clamp C and the bolt H.
Fig. 11. Lathe with Taper Attachment arranged for Boring Taper Hole in Engine Piston