Patent GB-771691-A (GB)
Title: An improved brushing mechanism
Inventor: NELSON BROOKS EDWARD
IPC: B24B47/06
Filed: 1954-06-01
Abstract: 771,691. Brushing machine. OSBORN MANUFACTURING CO. June 1, 1954, No. 16240/54. Class 60 [Also in Group XXXVII] A brushing mechanism; e.g. for removing burrs from gear teeth, comprises a rotary brush and drive means therefor, a work-piece support, means operative to effect relative movement of the brutsh and support toward and away from each other to present the work-piece to the brush,and to space the work-piece away from the brush, and automatic control means for the brush drive means effective to reverse the direction of rotation of the brush. In a machine for removing burrs from the teeth of a gear 63 by power driven rotary brushes 64, 65 the gear 63 is held by a mandrel, chuck or collet 62 carried by an upper housing 52, lower housing 51, guide shoe 39, main slide 24, cross-slide 16, and cylinder 3. The cylinder 3 is vertically adjustable on a fixed inner cylinder 2 mounted on a base plate 1. The cylinder 2 contains oil and is connected through pipe 10, containing a valve 9, with cylinder 3 above the closed end of cylinder 2; the cylinder 2 is also connected through pipe 8, containing a valve 11, with a source of compressed air. Movement of the cylinder 3 is limited by a piston 6 carried thereby enclosed in a cylinder 7. An oil filler tube 12 carries a scale 14. The cylinder 3 can be adjusted around a vertical axis, and is secured in vertically and rotatably adjusted position by a clamping ring 5.  The cylinder 3 carries a platform 4 having bolted thereto a slideway 17 on which the cross-slide 16 is movable by a screw and ball crank 18; a pointer on the slide co-operates with a scale on the slideway. Sheet metal housings carried by the slide protect the exposed end portions of the slideway.  The cross-slide 16 carries 'a slideway 23 on which the main slide 24 is movable by. screw 25 and ball crank 26; a pointer 27 on the slide co-operates with a scale 28 on the slideway. A housing 29 carried by the slide shields the forwardly extending portion of the. slideway.  The main slide 24 carries a fluid-pressure piston-cylinder assembly comprising a cylinder 30. One cylinder head 31 being press fitted in a mounting plate 38 bolted. to box frame 37 carried by slide 24. A piston'34 is secured on a tubular piston rod 33 by locking rings 35, 36, which space the piston from the cylinder heads at the ends of the stroke.  The forward end of the piston rod 33 carries the guide shoe 39; guide pins press fitted in the shoe slide through bushings in cylinder head mount 38 to prevent rotation of the shoe about the axis of piston rod 33.  A drive shaft 45,- journalled within tubular piston rod 33, has a bevel gear 46 keyed to one end thereof adapted to enter into driven engagement with a bevel gear 43 driven through speed reducer 44 by an electric motor 42 mounted within box frame 37. The gear 46 is secured to shaft 45 by a sliding keyway permitting slight axial movement; a spring 47 interposed between gear 46 and a stop ring 48 secured to the shaft urges the gear 46 towards gear 43.  A sheet metal housing 49 secured to shoe 39 encloses the piston-cylinder assembly 30, 34, shaft 45 and gear 46; the housing is supported by rollers 50 mounted on cylinder 32. Secured to the shoe 39 is a universal work-carrying head comprising a lower housing 51 and an upper housing 52 connected for rotative adjustment about an axis normal to the axis of the shaft 45. Lower housing 51 is secured to shoe 39 by locking screws passing through arcuate slots in the housing flange concentric to the axis of the shaft 45; while the length of the slots limits normal adjustment about the axis of shaft 45, the locking screws may be removed temporarily and reinserted after the head has been turned the desired extent. Scales may be provided to facilitate setting-up. A bevel gear 56 keyed to an extension 57 of drive shaft 45 engages bevel gear 58 within lower housing 51, which gear drives bevel gear 59 meshing with,'bevel gear 60 on shaft 61 within upper housing 52. Shaft 61 carries a mandrel, chuck or collet 62 to hold the work-piece 63. An overhead air line 67 to which air line 8 is connected also leads to solenoid operated four-way valve 68 adapted to admit air under pressure to either line 69 or 70. leading respectively to opposite ends of cylinder 30. Operation of the valve 68 is controlled by a timer 71; on pressing button 72, the normally open timer contacts 73 are caused to close, energizing a solenoid 68<SP>1</SP> which operates valve 68 to cause advance of the work-carrying head. After expiration of the time interval for which the timer is set, contacts 73 automatically open, de-energizing solenoid 68<SP>1</SP>, the valve 68 then effecting withdrawal of the work-carrying head. To enable the work-carrying head to be reciprocated at will by the operator during setting-up, a manual switch 74 is provided to operate solenoid 68<SP>1</SP>, by-passing the timer. Manual switch 75 on a separate circuit is provided to energize motor 42 as well as the mechanism of timer 71. A toggle switch 76 mounted on the box frame 37 has a spring-backed operating plunger 77 adapted alternatively to connect clockwise holding coil 78 or counterclockwise holding coil 79 of a magnetic reversing starter 91 for brush drive motor 80 in circuit with power lines L<SP>1</SP>, L<SP>2</SP>. A ratchet 81 also mounted on frame 37 has diametrically opposed cams, 82, 83 for actuating the plunger 77 of toggle switch 76, so that each time ratchet 81 is rotated a quarter turn brush drive motor 80 will be reversed. The ratchet 81 is activated by a pawl 85 on a link 86 co-operating with spaced abutments 88, 89 on the housing 49; during the retraction of the workpiece out of engagement with the brushes, abutment 89 rocks link 86 so rotating ratchet 81 to cause reversal of the brush. drive motor, and on the next advance movement of the work-piece the abutment 88 returns the link 86 to its inverted position. The arrangement may be such that reversal of the brush drive motor takes place in response to any desired number of reciprocations of the work-piece carrying head. A solenoid operated magnet brake 90 may be provided for the motor 80, the brake being. applied simultaneously with operation of the toggle switch 76. The, timer may be set automatically to reenergize the solenoid of valve 68 after the expiration of a predetermined loading period to present the new work-piece to the brushes without the necessity of the operator pushing the "Start" button. ' . In a modification, the work-carrying spindle is backed by resilient means to reduce the shock of initial impact of the brush with the work.