Fig. 767.
[Fig. 765] represents an excellent driver for cored work such as the piece w. Its hub a is screwed on the live spindle in place of the face plate, and carries the rods b, b′, both of which are adjustable in the distance they stand out from a, so that b may be set to suit the work, and b′ set out sufficiently to balance b and d. The driving arm d is adjustable along b, and by being bent to the form shown is more out of the way, and obviates the necessity of using a dog on many kinds of work. The other end of the work is shown supported by a cone centre c, whose construction is shown in [Figs. 766] and [767]. Its object is to avoid the wear that occurs at the mouth of the hole in cored work, when it is run on the dead centre, and to avoid the necessity of plugging the hole to provide a temporary centre. In the figures, a represents a stem (fitting into the tailstock spindle s, in place of the ordinary dead centre), having a collar b and carrying the cone c. The work is supported upon c, which revolves upon the stem of a. At e is a raw-hide washer, intended to prevent the abrasion which would occur on the faces of b and c. The pin f prevents c from coming off d, one half of its cross section being in c, and the other half in a semicircular groove running around d. An oil groove is provided through the collar b, and passes along the stem d. This is an exceedingly handy device for cored work, and may also be used to sustain work against the lathe face plate, while chucking the work true by its bore.
The work drivers employed by wood turners, for work held between the lathe centres, are as follows:—
Fig. 768.
Fig. 769.