Patent GB-571862-A (GB)
Title: Improvements in honing machines
IPC: B24B33/10
Filed: 1943-11-12
Abstract: 571,862. Honing-machines. BURGESS, A. F. (Barnes Drill Co.). Nov. 12, 1943, No. 18860. [Class 60] A honing machine, described as for operating on a cylindrical bore, has an actuator to give rapid expansion of the hone into engagement with the work and a second actuator to effect positive expansion of the hone in regular increments during operation, with control mechanism governing selectively the operation of the two actuators. The machine comprises a column 10, Fig. 1, with guides 11 on which a tool head 12 is mounted to reciprocate ; the tool is carried by a tubular spindle 14. The spindle 14 is driven through a splined shaft 20, Fig. 4, and gears 21, 23 by an electric motor M, and the head 12 is reciprocated by a piston 25 in a cylinder 26, fluid passing to the cylinder from a pump P through a reversing-valve RV operated under control of a pilot valve PV actuated by a movable control rod 29 with stops 30-32 thereon engageable by a dog 33 on the head 12. The hone comprises stones 35 adjustable radially in a carrier 36 by an adjusting rod 37 extending axially through the spindle 14 and operable by fluid actuators 40, 41 to which pressure fluid is supplied by a pump P' ; a relief valve V<4> is employed and a pressure-regulating valve V<5> may be placed in the line leading to the actuator 41. The actuators 40, 41 operate through a tubular actuating member 42 connected to the rod 37 by means of a member 43 slidable in the lower end of the member 42 to an extent limited by a pin 46 in the member engaging slots 47 in member 43, and pressed by a spring 48, the tension of which is adjustable by a bar 49 in the member 42 adjustable by screw plugs 50, 51. The lower end of the member 43 engages an antifriction thrust bearing 52 carried by a part 53 secured to the rod 37 and engaged by a spring 55 located in a counterbore in the spindle 14 ; the spring 48 serves to prevent the application of excessive pressure to the honing tool. The actuator 40 gives a continuous advance to give rapid initial expansion to the hone, and comprises a piston 60, on the member 42, working in a cylinder 61 carried by the head 12, fluid being introduced or exhausted by a pipe 62 ; the piston is formed with a hollow extension 63 with an internal flange 64 adapted to bear on the member 42, the extension 63 also carrying a nut 66 to act as a stop to limit movement of the piston. The actuator 41 is arranged to advance the member 42 in successive steps to give positive expansion of the tool and is operated intermittently to rotate the member 42, with a screwed part 71 in engagement with a stationary nut 70. The actuator comprises a piston 72 working in a cylinder 73 and having a piston-rod 74 with rack teeth thereon meshing with a pinion 76 between collars 77 fixed on the member 42, movement of the pinion being transmitted to the member 42 through a one-way clutch, so that the piston 72 may return without operating the member 42 ; the piston is given its operative stroke by fluid admitted through a pipe 79 and is returned by a spring 81, the stroke being determined by a stop 80. The nut 70 is in the form of a block slidable into and out of engagement with the screw 71 by a piston 83 in a cylinder 84, the piston being moved to engage the nut with the screw by fluid entering by a pipe 89 and returned by a spring 88. The cylinders 84 and 61 are connected in parallel through a valve SV which allows pressure fluid to pass to the pipe 89 only when the pressure in the pipe 62 builds up at the end of the traverse of the piston 60.