US2728171A - Surface finishing mechanism - Google Patents

Description

Dec. 27, 1955 J. E. O'NEILL SURFACE FINISHING MECHANISM l t e w e h 90 S b 6 e h S m 5 m w m w 3 5 9 l O 5 l l m. A d a l 1 FL INVENTOR JQSEPH E. Q NEELL %zd@2'@@- Q/gwmw A TOR EY$ 5 Sheets-Sheet 2 Filed April 50, 1953 INVENTOR E! L L 5 She ets-Sheet 5 Filed April 30, 1955 ATTORNEYS u 92 m MN G m mh E #3 a Q mm 8 0v. JB nm On 5 l mdE Dec. 27, 1955 J. E. O'NEILL SURFACE FINISHING MECHANISM 5 Sheets-Sheet 4 Filed April 30, 1953 a O 8 ME H fl m m0 mm H P E 6 S Y o B J m a I \1 l I F x Dec. 27, 1955 J. E. O'NEILL SURFACE FINISHING MECHANISM 5 Sheets-Sheet 5 Filed April -30, 1953 INVENTOR. JOSEPH E. O'NEILL w wm- (QJ M ATTORNEYS SURFACE FINISHING IVECHANISM Joseph E. GNeill, Washington, D. 0. Application April 30, 1953, Serial No. 352,315

7 Claims. (CI. 51-67) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to surface finishing, and particularly to the smoothing and polishing of cylindrical surfaces of workpieces while in position upon a metal- Working machine, as for example, an automatic screw machine having single or multiple spindles.

In the preparation of close-tolerance machine elements, particularly small parts designed to have snug fits in cylinder bores or the like, the present procedure in many shops is to perform the major machining operations in an automatic screw machine, then to remove the piece from the screw machine and place it in a lathe for a final grinding or polishing operation to achieve the required closetolerance or micro-inch finish.

The present invention makes it possible to achieve the necessary polished finish on suchworkpieces without resort to a separate grinding or polishing machine. To this end an object of the invention is to provide means for performing a surface polishing operation as a sequel to the principal machining operation without detaching the workpiece from its anchorage in the screw machine or lathe where it had previously been mounted for the drilling, tapping, grooving or other operation or operations constituting its principal machining requirements.

Another object is to provide surface polishing means in the form of a flexible band or tape coated or otherwise treated to present an abrading surface; the flexible tape being controlled in such way as to maintain continuous contact with the surface to be polished as the latter is rotated by the conventional workpiece rotating means of the screw machine or lathe in which the piece is mounted.

A third object of the invention is to provide means for causing the tape to oscillate, that is, partake of a limited sidewise shifting, cyclically to the left and right and altcrnately of the longitudinal center line of the tape while at the same time maintaining the tape in firm contact with the surface of the rotating workpiece.

A fourth object is to provide means utilizing the conventional transverse motion of the cross slide assembly of the machine to actuate a tape-feeding mechanism, which mechanism is itself a further feature of the invention.

A fifth object is to provide means for regulating the extent of advance of the tape on each cycle of operation of the above-mentioned tape-feeding mechanism.

A sixth object is to provide a novel assembly of parts for supporting and operating the flexible polishing tape, which novel assembly lends itself to quick attachment as a unit to the cross slide of the screw machine or lathe holding the piece to be polished.

A seventh object is to provide, as part of the novel assembly just referred to, a mechanism for readily adjusting the assembly to accommodate workpieces of different diameters.

Other objects and many of the attendant advantages of States Patent '9 2,728,171 Piatented Dec. 27, 1955 views of the supporting frame for the pivotal yoke of Figs. 4 and 5;

Fig. 8 is a view similar to Fig. 1, but showing the tape advancing linkage in its opposite extreme position; and

Fig. 9 is a sectional view on line 99 of Fig. 1.

In the drawings reference numeral 1 designates a chuck of a screw machine or lathe to which chuck a workpiece 2 may be secured in conventional manner forming no part of this invention. A conventional cross slide is shown at 3, said cross slide being adapted in the usual manner to receive a cutting tool or tools (not shown) for performing machining operations in a conventional way as the cross slide traverses the length of its stroke with the chuck 1 and workpiece 2 being rotated by the spindle drive motor of the machine (not shown).

A band or tape 4 of emery cloth or other suitable abrasive-carrying fabric is illustrated as having its source in a feeding spool 5 and its destination at rewinding spool 6, both spools being journaled in the two parallel Wings 21 and 22 (see Fig. 7) of a frame element 12 suspended beneath the cross slide 3 as by screws (not shown) whose heads are retained in the horizontally extending slots 24 of the cross slide. Also journaled in the wings 21 and 22 of the frame is a pivotal yoke 13 having horizontal arms 26 and a vertical leg 27, the latter receiving an upper subassembly 28 and a lower subassembly 29. Upper subassembly 28 carries a cylindrical roller 9 freely rotatable therein and adapted to ride rotatably upon the upper surface of the workpiece 2 as the latter is rotated by its spindle 1. Screws 10 and 11 are preferably made shiftable to adjust vertically and horizontally (within the limits of slots '7, Fig. 3) the position of subassembly 28 upon the vertical face of leg 27, thereby regulating the position and pressure of roller 9 upon the workpiece in accordance with variations in the lengths and diameters of pieces successively placed on the spindle 1.

The lower subassembly 29 which is attached to vertical leg 27 of the yoke assembly includes a platen or carriage 30 equipped with a trough 31 of rectangular contour with a U-shaped cross section. A block 8 of relatively yieldable material such as soft wood or rubber is inserted into the trough 31, the block being rounded along its upper surface to serve as a supporting bed for the tape 4 as the latter passes around the members 29 and 30 being guided by rollers 33 on its way to receiving spool 6.

The carriage 30 has a toe piece 34 supporting a vertically disposed post 35 carrying a freely rotatable cam follower 36 constantly pressed as by spring 37 against the cam-surfaced face of a sleeve 1' secured to chuck 1 to rotate therewith; the spring 37 being retained by aligned recesses in the carriage 30 and the body 29, respectively. To facilitate sliding of the carriage upon the upper horizontal surface of the body 29 and for retention against sidewise displacement, the adjacent surfaces of both parts are dove-tailed as indicated in Figs. 1 and 8.

The novel tape advancing mechanism includes a pair of tape advancing rollers 41 and 42 actuated by a' novel linkage shown in Figs. 1 and 8, and shown partly in Fig. 9 where rollers 41 and 42 are shown in section.

Both rollers have serrated or knurled cylindrical surweirfaces a t to it into the su e o he tap 4 and thus cause the tape to move forward in response to rota tion of the driving roller 41. Roller 41 is journaled in arms 26 of yoke 13, and is normally at rest, but is capable of turning through a small are as yoke 13 swings from the Fig. 1 position to the Fig. :8 position; the exact degree of turning being determined by the adjustment of stop screws .43 mounted in crossbar d4. Turning of the roller 41 is effected automatically at the conclusion .of .each cycle ,of operation of the screw machine or lathe at which time the cross slide 3 moves to the right, as viewed in Fig. l, causing roller 9 to roll down the side of the workpiece 2 and permitting the entire yoke assembly 13 to swing (of its own weight aided by spring 82) from its normal horizontal attitude .(Fig. l) to the drooping position shown in Fig. 8. This downward swing turns rollers at and 42 and causes the tape 4 to move forward a fraction of an inch, the exact amount of advance depending upon the adjustment of screws 43 in crossbar 44; the swing ceasing when the heels 43 .of yoke 13 strike theends of screws 43. The manner in which the downward swing of yoke 13 is translated into a turning of rollers 41 and 42 will now be described.

Turning of the rollers 41 and 42, and simultaneous winding of the tape 4i onto the receiving spool 6, is accomplished by the novel linkage shown in Figs. 1 and 8. As there shown the linkage includes a pair of ratchet wheels Stand 52, pawls 53 and 54, bell cranks 55 and 56, and a connector link '7 tying together the pivot pins 58 and 59 of the bell cranks 55 and 56, respectively; the pawls 53 and 54 being also pivotally mounted on the bell cranks 55 and 56, respectively. The shank 61 of hell crank 55 is keyed to the arm 26 of yoke 13 by key 45 (see Fig. 2) while inner shaft 46 is secured by key 47 to the bore of tape advancing roller 41.

Hub 4') of ratchet wheel 51 is secured to shaft 46 by taper pin 59 (Figs. 2 and 9) while shank 62 of bell crank 56 runs freely on the spindle or axle 63 to which the spool d is secured, as by .setscrew 64 (Fig. 2). However, the pawl 54 is constantly engaged with the teeth of ratchet wheel 52, and the latter is pinned (at 66) to the axle 63 of spool 6, hence movement of link 57 to the right is translated into turning of spool 6 in a counterclockwise direction and therefore the tape 4 is wound onto the spool each time link 57 moves to the right in response to downward swing of yoke 13.

Downward swing of yoke 13 is also translated into a turning of rollers ll and 42 to advance the tape as heretofore noted. This is accomplished by way of pawl 53 and ratchet wheel 51. That is, the downward swing of the yoke causes a corresponding swing of bell crank 55 and hence ofihe pawl 53 mounted on said bell crank. The pawl thereupon turns the ratchet wheel 51 and the shaft 46 (pinned thereto) in a counterclockwise direction; and as roller 43. is keyed to shaft 46, it also partakes of this counterclockwise turning. This turning imparts a corresponding turning (in the opposite direction) to roller 42, and the intermeshed motion of the two rollers advances the tape proportionately, to be wound upon the spool '6; the spacing or pitch of the ratchet teeth of wheels 51 and 52 being of sufficient fineness to insure accurate winding of the tape for all degrees of adjustment of total cyclic winging of the yoke as determined by the setting of adjusting screws 43.

()n the return (upward) swing of yoke 13 the two pawls 53 and 54 overrun their respective ratchet wheels, and, therefore, there is no reverse motion of reel 6 or roller 41. Thus, the tape 4 is advanced periodically and by stages upon each successive downward swing of the yoke 13, but remains stationary during the successive return (upward) swings of the yoke.

To restrain any tendency of reel 6 to drift backward as pawl 54 draws back on the reverse swing of the linkage a friction brake block'67 (Fig. 2) is urged by spring 68 aga-instthe surface of'rirn 69 of reel 6; the brake block .4 being flanged for retention in brake housing 70 mounted in frame 12 and the brake pressure being regulatable by turning adjusting screw 71 which is threaded into the frame.

To provide for adjustment of the pressure of rollers 41 and 42 against the tape 4 the roller 42 is mounted upon an eccentrically turned central portion 72 (see Fig. 9) of a bearing spindle whose end portions 73 and 74 are supported on bushings 75 and 76, respectively, provided in wings 21 and 22 of the frame 12. The spindle end 74 is reduced and squared, as at 77, to receive a wrench or similar tool by which the spindle may be rotated to vary the degree of eccentricity in the common plane of the two roller axes, thus varying the pressure of the rollers upon the tape 4. To lock the spindle in the adjusted position there is provided a notched ring 78 and a pin 79 (see Fig. 1) engageable with one or another of the ring notches to hold the ring against further turning so long as the pin remains in position; the .pin having a head 80 to facilitate insertion into and withdrawal from the frame 12, and the ring 78 being provided with a setscrew 81 by which it is locked to the spindle to maintain the latter in adjusted position.

A coiled compression spring 82 occupies aligned recesses in the frame 12 and yoke 13 and serves to take up the shock as the yoke and roller 9 ride back onto the workpiece 2 in moving from the Fig. 8 position up to the Fig. ,1 position.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. Means for polishing the surface of a cylindrical workpiece while it is mounted on a work rotating machine, said polishing means comprising a flexible polishing tape having tangential contact with the cylindrical surface to be polished, a spool to which one end of said tape is anchored, a cross slide movable toward and away from said workpiece, and means responsive to movement of said cross slide away from said workpiece to cause a predetermined length of said tape to be wound upon said spool, and thereby to present a new segment of the tape for tangential contact with the workpiece surface to be polished.

2. Means for polishing the surface of a cylindrical workpiece while it is mounted on a work rotating machine, said polishing means comprising a flexible polishing tape having tangential contact with the cylindrical surface to be polished, a cross slide movable toward and away from said workpiece, and means responsive to movement of said cross slide away from said workpiece to cause said tape to advance and present a new surface to the workpiece surface to be polished.

3. -Means for polishing the surface of a cylindrical workpiece while it is mounted for rotation with a work rotating machine, comprising a flexible polishing tape having tangential contact with the cylindrical surface to be polished, a cross slide movable toward and away from said workpiece, a base releasably attached to said cross slide, a platen supporting said polishing tape, an element ridabl e on said workpiece directly above said platen, means pivotally mounted on said base for supporting both said platen and said ridable element, said means operating to swing both said tape and said ridable element away from said workpiece in response to movementof said cross slide away from said workpiece, and means responsive to operation of said swinging means to cause said tape to advance and thus present a new surface to the workpiece surface to be polished.

4. 'Means for polishing the surface of a cylindrical workpiece whileit is mounted for rotation with a work el tin m h n awaitin a fist ble polishing t having tangential contact with the cylindrical surface to be polished, a cross slide movable toward and away from said workpiece, a base releasably attached to said cross slide, a platen supporting said polishing tape, an element ridable on said workpiece directly above said platen, means pivotally mounted on said base for supporting both said platen and said ridable element, said means operating to swing both said tape and said ridable element away from said workpiece in response to movement of said cross slide away from said workpiece, and means rotatable with said work rotating machine for causing said tape to have limited sidewise motion, both to the left and to the right of the longitudinal axis of the tape, while maintaining tangential contact with the rotating cylindrical workpiece.

5. Means for polishing the surface of a cylindrical workpiece while it is mounted for rotation with a work rotating machine, comprising a flexible polishing tape having tangential contact with the cylindrical surface to be polished, a cross slide movable toward and away from said workpiece, a base releasably attached to said cross slide, a platen supporting said polishing tape, an element ridable on said workpiece directly above said platen, means pivotally mounted on said base for supporting both said platen and said ridable element, said means operat ing to swing both said tape and said ridable element away from said workpiece in response to movement of said cross slide away from said workpiece, a tape receiving spool, and means responsive to the operation of said swinging means to cause said spool to be rotated a fraction of a revolution, thus causing said tape to be wound upon said spool.

6. Means for polishing the surface of a cylindrical workpiece while it is mounted for rotation with a work rotating machine, said means comprising a flexible polishing tape having tangential contact with the cylindrical surface to be polished, an element ridable on said Workpiece directly above the line of tangential contact of said workpiece and flexible tape, means responsive to the conclusion of the cycle of operation of said machine for causing said ridable element and tape to swing out of contact with said workpiece, and ratcheting means for advancing said tape in response to operation of said swinging means.

7. Means for polishing the surface of a cylindrical workpiece while it is mounted for rotation with a work rotating machine, said means comprising a flexible polishing tape having tangential contact with the cylindrical surface to be polished, an element ridable on said workpiece directly above the line of tangential contact of said workpiece and flexible tape, means responsive to the conclusion of the cycle of operation of said machine for causing said ridable element and tape to swing out of contact with said workpiece, and means operated by said machine for transversely oscillating said tape along the line of tangential contact with said cylindrical surface.

Miller Oct. 29, 1889 Calahan May 7, 1912

Images