GB1130132A - Improvements in and relating to tool holders - Google Patents

Abstract

1,130,132. Boring bars, vibration dampers. N. E. SHURTLIFF. 7 Dec., 1965, No. 51732/65. Headings B3B and B3C. A boring bar 10, Fig. 1, comprises a vibration damper rod 24, which prevents the cutting tool 18 from chattering. The bar has a blind bore 12 which provides divergent surfaces 14, and the end of rod 24 provides an abutment surface 30. The abutment surfaces may be of any of the forms of Figs. 3 and 5 (not shown), and the periphery of the rod may be of any of the forms of Fig. 4 (not shown). Rod 24 may be filled with lead, tungsten, or other metal chips, suspended in oil or mercury, or sand suspended in mercury, or it may be formed as a lead bar surrounded by mercury. The inner end of the rod is closed and centred by a spring-urged plug 32, and graphite or molybdenum sulphide lubricant may be introduced into the space between bar 24 and bore 12. In a modification, rod (64), Fig. 6 (not shown), has abutment surfaces (68) at both ends which co-operate with abutment surfaces (70). In a further modification, the vibration damper rod 144, Fig. 8, is mounted on a bar 130, and is spring urged so as to engage an abutment surface 142 on a collar 136 secured to bar 130. The tungsten and mercury chips 150 are located in a casing 148.