Patent GB-761086-A (GB)
Title: Fluid pressure gauge for use with honing tools
IPC: B24B33/06
Filed: 1954-01-18
Abstract: 761,086. Honing. BARNES DRILL CO. Jan. 18, 1954 [Aug. 19, 1953], No. 1480/54. Class 60 [Also in Group XIX] A machine for honing a cylindrical bore 10 in a workpiece 11 has a head 12, reciprocated by a fluid operated actuator 13, in which is journalled a spindle 14 driven from a power shaft 16 and carrying a honing tool 15. The latter comprises a body 19 having radial guides for the carriers 21 of abrasive stones 22 normally contracted by springs 23; the carriers bear through pins 21a against conical cams 25 on a rod 26 connected to the piston of an actuator 29. The tool also comprises fibre guides 24. A device for gauging the size of the cylindrical bore being honed includes orifices 27 supplied with pressure fluid through a common flexible conduit 28 and floatingly mounted on the hone body 19 to direct jets of fluid against the wall of the bore 10, thereby causing the pressure in the conduit to change as the position of the work surface is changed by the action of the honing stones 22. Each orifice 27 is at the end of a nozzle comprising a tubular plug 30 pressed into a shoe 31 attached by screws 32 to radial lug 31a on the periphery of a carrier ring 33 mounted for free transaxial floating relative to the hone body in a groove 34 therein; rotation of the carrier ring relative to the body 19 is prevented by a pin 35 engaging a slot 34a in the carrier ring. The bores 30a of the plugs 30 communicate through radial holes with an annular passage 37 connected to the lower end of the flexible conduit 28; the latter lies in a notch in the body. The outer ends of the orifice holes 30a through the plugs 30 are enlarged at 42 by counterboring the shoes 31; the counterbore may be enlarged by short horizontal wings 43. Inclined surfaces 31b at the-outer ends of the shoes 31 engage the bore wall and guide the carrier ring 33 into the bore as the honing tool is advanced into the work at the start of a new cycle. The flexible conduit 28 extends upwardly along the spindle to a transfer ring 39 sur- 'rounding the spindle and formed in part by a non-rotatable collar 40 movable up and down with the head 12. The transfer ring 39 communicates through conduit 43 with pipe 44 supplied with liquid under pressure by a motor driven coolant pump 45 constancy of supply pressure being maintained by an accumulator 46 and an automatic valve 47; pressure delivered to the conduit 43 is adjusted by a valve 49 and is indicated on gauge 50. Pressure changes in conduit 43 due to changes in the size of the work bore during a honing cycle cause movement of a wall 52 of bellows 53, the wall being coupled to an arm 54 fulcrummed at 54a and carrying the movable contact of a switch 55. To eliminate the effect of changes in the supply pressure, a by-passage 62 communicates with the supply line 44 through adjustable valve 64, with an escape orifice constituted by adjustable needle valve 63, and with the wall 66 of a bellows 67 opposed to bellows 53. The power actuators 13, 29 are controlled in a manner to continue the reciprocation of the honing tool beyond the time of initial closure of the switch 55 and until this switch has remained closed continuously for a full stroke of the honing tool; this control is achieved by a timing device 68. This is activated by closure of the switch 55; upon subsequent opening of the switch the timer is reset automatically, and when it is energized for a predetermined interval, determined by adjustment of a knob 69, a solenoid 70 is energized to close a switch 57 thus energizing a signal lamp 58 to indicate that the entire length of the bore is to size and to open a switch 56 which controls a lamp 59 indicating that the bore is undersize. To provide for "sparking out", the honing tool is. reciprocated within the bore without further expansion, this being effected by a timer 60 energized when the switch 57 is closed and then operating. after the lapse of an interval determined by adjustment of knob 60a, to close switch 60b. This completes a circuit for energizing a relay R1 for causing the honing tool to be fully withdrawn from the work bore. Closure of the switch 57. also completes a circuit for energizing a solenoid R2 to close a valve 87 controlling the actuator 29 so as to stop expansion of the honing tool. The control system is similar to that described in Specification 601,526.