499,637. Honing cylinders &c. BURGESS, A. F. (Barnes Drill Co.) April 27, 1938, No. 12588. [Class 60] In a machine in which a honing tool is repeatedly passed over the surface of a work piece by relative reciprocation of a table supporting the work and a carriage which supports the spindle of the tool, the tool is rotated by a variable speed rotary hydraulic motor. The reciprocation may be effected by a second hydraulic motor. As shown, the work-table 9, Fig. 1, is adjustably supported on slideways 8 on a frame 7 beneath a reciprocating spindle carriage 12 mounted on a base 13 having pairs of spool-shaped rollers 17 engaging cylindrical guide bars 10. Each roller is surrounded by a guard 23, Fig. 3, and consists of two chamfered bearing units 18 separated bv a sleeve 20 and mounted on a stud 19 which is eccentrically carried on a sleeve 24 to enable the roller to be moved into tight engagement with the guide bar. An extension 26 on the frame 7 houses a multicylinder rotary hydraulic motor 30 which through gearing 32, 33 rotates the spindle 31 of the tool. The speed of the motor is varied by a hand wheel 49 which, through gears, rotates a sleeve to shift a rod 39 axially and adjusts the angular position of a head section 36 of the motor relative to a drive section 35. A tachometer 50a on the spindle carriage indicates the speed of the spindle. The extension 26 is also provided with a vertical bore 27 in which slides a piston 28 connected to the carriage by a rod 29. To relieve the hydraulic motor, formed by the piston 28 and cylinder 27, of the weight of the carriage 12, the latter is connected to a piston which is exposed to air under pressure and reciprocates in a cylinder (not shown) at one side of the extension 26. The motor 30 is supplied, through conduits 59, 65, Fig. 7, controlled by a valve 60, with fluid under constant pressure by a pump 51 mounted at the bottom of the frame 7 and driven by an electric motor 53. The hydraulic motor 27, 28 is supplied with fluid from a pump 52 which is driven by a belt 55 from the pump 51 and provided with a regulating member 83 which is adjusted by a hand wheel 88, Fig. 1, to control the reciprocating speed of the carriage 12. The pump 52 supplies fluid past a valve 68, Fig. 7, to a conduit 69 which divides into two branches, one 70 containing a pilot valve 71 and the other 72 being connected, beyond a non- return valve 80, to the lower part of the cylinder 27 and beyond a reversing valve 73 to the upper part of the cylinder 27. With the pilot valve in one position, fluid is supplied to the left-hand side of the reversing valve 73 to move it axially and cut off the supply of fluid to the top of the cylinder ; the fluid then passes through the pipe 72 into the bottom of the cylinder 27 and raises the carriage 12. When the pilot valve is turned, fluid is supplied to the right-hand side of the reversing valve 73 and moves it axially to allow fluid to pass to the top of the cylinder 27 to lower the carriage 12. At starting, levers 99, 100, Fig. 1, are released by a lever 101 and the lever 100 is turned to set the valve 68 in the running position in which fluid from the pump 52 is supplied to the upper end of the cylinder 27, the lever 99 is then brought into locking position with the lever 100 and opens the control valve 60 to supply fluid from the pump 51 to the motor 30. As the carriage 12 moves downwards, an arm 111, Fig. 3, attached thereto moves downwards in a slot 112 in the frame 7 over a spring-pressed stop 109, Fig. 4, until the arm 111 engages a stop 108a on a control rod 105. Further downward movement of the carriage then lowers the rod 105 and causes collars 126 through a lever 125 to rock a shaft 122 and operate the pilot valve 71 which in turn operates the reversing valve 73 to effect a reversal of the supply of pressure fluid to the carriage 12. The carriage then moves upwardly until the arm 111 engages the stop 109 and shifts the control rod 105 to operate the pilot valve to reverse the movement of the carriage. Reciprocation of the carriage 12 between the stops 109, 108a continues until the stop 109 is moved out of the path of the arm 111 by rotating the rod 105 either manually by a lever 113, Fig. 1, or by a solenoid 114, Fig. 3, which is energized after a definite number of reciprocations of the carriage 12 has been recorded on a register 130, Fig. 4, by a bar 128 attached to the lever 125. The carriage then moves upwardly until the arm 111 engages a stop 108 and during this movement a cam 103, Fig. 1, engages an arm 102 and returns the locked control levers 99, 100 to their initial position and closes the valves 60, 68 to stop the rotary and reciprocating hydraulic motors. When the arm 111 engages the stop 108, the pilot valve 71 is reversed so that when the machine is again started the carriage 12 moves downward. During the return of the carriage 12 to its starting position, an arm 133, Fig. 3, engages a. rod 131 which through a rack-andpinion 134, Fig. 4, resets the counter 130.