Patent GB-1148821-A (GB)
Title: Improvements in or relating to honing equipment
Inventor: COX ALAN JOHN
IPC: B24B33/08
Filed: 1966-02-11
Abstract: 1,148,821. Honing. DELAPENA HONING EQUIPMENT Ltd. 15 March, 1967 [11 Feb., 1966], No. 6022/66. Heading B3D. Honing equipment comprises a honing head with two sets of stone mountings and a central expander wedge arrangement, a centralized axial position of the expander wedge corresponding to retracted positions of both sets of stone holders and axial movement of the wedge in either direction expanding the corresponding set radially to an operative position without intermediate angular movement of the wedge, and control means operative to provide positive centring of the wedge. A honing tool, Figs. 1 and 2, carries roughing stones 13, finishing stones 14 and fixed guides 6. Expansion is effected by a wedge 18 comprising two integral end-to-end sections; each section has opposed frusto-conical parts 25 having longitudinal grooves 26 providing wings 27. The parts 25 are connected by a short cylindrical minimum diameter part 28. The wings 27 on one part 25 are aligned with the grooves 26 on the other part 25. Limbs 29 associated with the roughing stones 13 are aligned with the wings 27 on the right-hand parts 25 of the two sections, so that movement of the wedge 18 to the left from its central position expands the stones 13 against the action of spring rings 15; limbs 30 associated with the finishing stones 14 are aligned with the wings 27 on the left-hand parts 25 of the two sections, so that movement of the wedge 18 to the right from its central position expands the stones 14 against the action of spring rings 16. The wedge 18 has at one end a pin 11 engaging and slidable in a ring 31 having diametrically opposed pins 23 engaging longitudinal grooves 24 in the bore of the tool body so restraining the wedge 18 against rotation within the tool body 1 while allowing it to float laterally within the body. At the other end the wedge 18 is connected through a ball joint 20 to a short control rod 21 connected to a main control rod 22, Fig. 4, which may be universally jointed. The control rod 22 passes freely through a gear-box providing drive for rotating the tool and is connected through roller thrust bearings 42 with an end yoke on a piston-rod 36; the yoke has a projection 39 engaging a longitudinal slot 40 in a tubular mounting portion 33 to restrain the rod 36 against rotation with the control rod 22. The rod 36 is threaded into one extension 43 of an hydraulic control piston 35 working in a cylinder 37. A centralizing piston 47 in a cylinder 38 is slidable on the pistonrod 36 and has a greater effective area than the piston 35. When the piston 47 engages a step 48 at one end of the cylinder 38, engagement with the end of the adjacent piston extension 43 centralizes the piston 35 so that both sets of stones are fully retracted. Cycle.-Depression of push button START switch (1PB) energizes starter (1M) of the drive motor for pumps (53, 59) in the hydraulic control circuit. Depression of push button START CYCLE switch (2PB) energizes relay (1CR) energizing solenoid (25) operating valve (51) to provide hydraulic pressure from pump (53) for reciprocation of the honing tool, so that stroking of the tool into the bore commences. When the tool reaches the end of its inward stroke limit switch (2LS) is operated energizing relay (2CR) energizing solenoid (15) operating pilot valve (57) moving valve (58) to reverse the tool travel. At the upper limit of the outward stroke limit switch contacts (3LSa) are opened deenergizing relay (2CR) de-energizing solenoid (1S) so that the direction of travel is reversed. The tool thus reciprocates continuously. Initial energization of the relay (2CR) energizes relay (3CR) energizing starter (2M) for a drive motor for rotating the tool. Energization of relay (3CR) (i) energizes solenoid (3S) operating valve (62) to remove pressure from the space 63 of centralizing cylinder 38; and (ii) energizes solenoid (4S) operating valve (68) to supply hydraulic pressure to the end 70 of cylinder 37, thus moving piston 35 and centralizing piston 47 to the right to expand the roughing stones 13 at a pressure controlled by relief valve (77); the speed of movement is controlled by a restrictor valve (75). A pneumatic gauge is associated with the tool to enter the bore at each inward stroke of the tool. With undersize bore, contacts (SBa) are closed energizing relay (4CR) which is then held throughout the cycle. If manual size control is required, isolating switch (SBS) is opened so that relay (4CR) is not energized. When the desired roughing size is reached contacts (SBb) close; at the end of the next outward stroke of the tool limit switch contacts (3LSb) close energizing relay (5CR) (i) deenergizing starter (2M) to stop rotation of the tool; (ii) de-energizing solenoid (2S) to stop reciprocation of the tool; and (iii) energizing timer (TR) energizing solenoid (5S) operating valve (68) to supply hydraulic pressure to the end 72 of cylinder 37, thus moving piston 35 to the left to collapse the roughing stones 13 and expand the finishing stones 14 at a pressure controlled by relief valve (79), this pressure being lower than that used for expanding the roughing stones 13. Energization of timer (TR) also (i) isolates relay (5CR) from gauge contacts (SBb) and (ii) de-energizes solenoid (45) associated with valve (68). As the wedge 18 passes through the centralized position limit switch 1LS is opened by a cam 45 de-energizing relay (5CR), energizing starter (2M) and solenoid (2S) to restart rotation and reciprocation of the tool. After a time delay set on timer relay (TR) relay (6CR) is energized, (i) de-energizing solenoid (5S) and energizing solenoid (4S) thus operating valve (68) to supply hydraulic pressure to the end 70 of cylinder thus moving piston 35 to the right; and (ii) de-energizing solenoid (3S) operating valve (62) to apply pressure to the space 63 of centralizing cylinder 38. The wedge 18 is thus centralized. Energization of relay (6CR) de-energizes starter (2M) and tool rotation stops. Energization of relay (6CR) also shorts out outer limit switch contacts (3LSa) so that on the next outward stroke actuation of the limit switch is ignored and the tool is completely withdrawn from the finished bore, closing limit switch (4LS) energizing relay (7CR) de-energizing relay (1CR) with resultant de-energization of solenoids (2S), (4S), relays (2CR), (4CR), (6CR) and time relay (TR), thus restoring the machine to the conditions prevailing at the beginning of the cycle. Reference has been directed by the Comptroller to Specification 1,074,559.