Patent GB-379298-A (GB)
Title: Improvements in valve seating and cylinder boring devices
IPC: B23C3/05
Filed: 1931-02-24
Abstract: 379,298. Boring-bar machines ; portable turning apparatus. YERTSON, C. A., 1300, Garden Street, Hoboken, New Jersey, U.S.A. Feb. 24, 1931, No. 5726. [Class 83 (iii).] Boring-heads.-In portable apparatus for trueing valve seats or re-boring cylinders, of the kind in which a threaded feed spindle screws in a support attached to the work and acts on a cutter shaft mounted in the support, the cutter head carries radial centring dogs which are adjusted simultaneously by means of a common element to centre the head relatively to the valve seat or cylinder. For trueing valve seats, the apparatus comprises a plate 14, Fig. 1, having internal or external screw threads 14a for attachment to the valve 10 after removal of the valve cover. A central aperture in the plate is tapped to receive a hollow feed-screw 25 rotatable by a collar 26 thereon and having rotatable therein a tool shaft 27 driven by a handle 28. A cutter head 30, Figs. 1 and 2, is attached to the shaft 27 and carries both countersinking cutters 31 and facing cutters 32 for operating on the respective portions of the valve seat 11. The cutters are secured in grooves in the head 30 by a plate 37 attached by screws 39. Radial centring members 43 for engaging the walls of the valve seat are adjustable in further grooves in the head by a scroll plate 45 rotatable on a central stud 46 and locked by a nut 47. The cutters are fed to the work by rotation of the feed screw 25, collars 29 being secured to the shaft 27 to engage the ends of the screw through ball bearings. A nut on the screw 25 provides for locking it at any adjusted height. In a modified form of attachment a plate 18, Fig. 8, slotted at 19 may be secured to a flanged valve by studs &c., or two stepped blocks 21 may be adjustably secured to the plate by studs 22, flat projections 22<1>, 241 being provided on the blocks and on washers 24 respectively to slide in the slots 19. The central aperture 20 of the plate is screwed to engage the feed screw 25 and is set centrally with the aid of co-operating graduations. The steps of the blocks 21 are screwed for engaging internal screw threads on the valve, and the blocks may be screwed for engaging external threads. For small valves having a gland in the cover, the gland is replaced by a conical member 15, Fig. 6, secured by the gland cap 17 and screwed to receive the feed screw 16. To enable the operation of the cutters to be observed, sight apertures 55, are provided in the securing plates, as shown in Fig. 1. As applied to cylinder re-boring, the feed screw 14, Fig. 9, engages a screwed opening in a frame 11, 12, attached in any manner to the cylinder block 10. A support 15 for the screw has legs 16 straddling the frame 12 and also has an extension for supporting a driving handle 18 connected through bevel gearing 20 to the screw. The cutter shaft passes through the screw and is secured to it. The lower end of the tool spindle 22, Fig. 11, carries a head 37 in which the boring cutters 36 are adjustably secured by set screws 38. Upper and lower scroll plates 30, 31, serve to adjust radially the centring guides 25, 26 which are provided with balls 27, 28 for engaging the walls of the cylinder being bored, locking in the adjusted position being effected by a nut 35 on the spindle 22. In a modification, the lower guides 26, are replaced by additional cutters secured in adjusted positions by axially disposed screws in the body 37. Rotation of the feed screw 14 causes both the rotation and the axial feed of the cutters for boring.