GB425539A - Improvements in or relating to vibration dampening devices - Google Patents

Abstract

425,539. Grinding-machines. BADCOCK, F., 2, Allison Gardens, Dulwich Common, London, and KANE, R. W. H., Orchard End, West Road, Coombe, Surrey. July 17, 1933, No. 20172. [Class 60] [See also Groups XXXII and XXII] In a metal-cutting machine such as a grinding-machine, means associated with the toolholding and/or work-holding device are provided for damping vibrations set up during operation of the machine and comprise two members connected together so as to be capable of a limited amount of frictionallyrestrained movement relatively to one another against the action of resilient means which return the members to normal position. Fig. 1 shows a device for forming or trueing cylindrical surfaces and comprises a shaft 1 to which a tool-carrying head 2 is connected by a spring-pressed bolt arrangement 6, 8, the shaft carrying a resilient pin 12 engaging a larger sized hole 14 in the head 2. A friction washer 15 e.g. of cork separates the opposed faces 16 of the members 1, 2. When the cutting pressure exceeds a predetermined amount the head moves relatively to the shaft flexing the pin 12 which afterwards returns the head to its normal position. In a second construction a cutting-tool 26, Fig. 2, is fixed to a resilient bar 20 clamped at one end and frictionally connected at its other end by a spring-pressed bolt device 22, 24 to a member 19 secured to the shaft 1. In a modification, Fig. 4 when the resilient toolcarrying member 30 is deflected by undue pressure, inclined surfaces 33, 34 on the member 30 and on the head of a spring-pressed pin 35 carried by the tool-bar 32 coact with each other and oppose the return movements of the parts on rebound of the member 30. Fig. 6 shows a further construction comprising members 42, 43 clamped together directly or through springs 51, by bolts 48, pins 40, 41 of equal or different resiliency being secured to the member 42 and engaging larger-sized holes 44, 45 in the member 43. Relative rotative movement between the members due to excessive working pressure flexes the pins together or in succession straightening of the pins returning the parts. More than two pins may be used. In a modification a single central pin replaces the pins 40, 41 the vibration damping means being adapted to absorb slight rectilinear movements of the two members.