US2749670A - Abrasive finishing machine - Google Patents

Description

June 12, 1956 A. J. I Ewls, 3RD 2,749,570

ABRASIVE FINISHING MACHINE Filed March 5l, 1953 3 Sheets-Sheet 1 n v N Om O @QSQNOQ q) O wfoooo@ w \o O LQ G t \o INVENTOR ARTHUR d. Ew/s 3RD.

BY 9L ATTORNEYS 3 Sheets-Shea*- 2 A. J. LEWIS, 3RD

ABRASIVE FINISHING MACHINE INV 0R ARTHUR j Ew/s 3fm ATTORNEY5 June l2, 1956 Filed March 31. 1953 June 12, 1956 A J. I Ewxs, 3RD 2,749,670

ABRASIVE FINISHING MACHINE Filed March 31, 1953 3 Sheets-Sheet 3 INVENTOR f1 7-15 ARTHUR J Ew/s 3RD.

ATTORNEYS United States Patent O 2,749,670 ABRASIVE FINISHING MACHINE Arthur J. Lewis 3rd, New London, N. H., assignor to The Autoyre Company, Oakville, Conn., a corporation of Connecticut Application March 31, 1953, Serial No. 345,839 19 Claims. (Cl. 51-62) This invention relates to finishing methods and mechanism, and more particularly to methods and mechanism adapted for finishing work pieces such as rods of hot or cold rolled steel.

Numerous methods and mechanisms have previously been proposed for the finishing of such materials, but many of them have had numerous disadvantages, such as difficulty of adjustment, high cost, and non-uniformity of finish, and itis accordingly an object of the present invention to provide method and mechanism for overcoming these difficulties.

Another object is to provide a method and means for effecting a reduction in the size of hot rolled steel wire while at the same time producing a rod having a smooth and relatively soft surface.

A further object is the provision of method and means for abrasively nishing and polishing rods of steel and other materials.

Yet another object is the provision of method and means for finishing and polishing such rods by means of abrasive tape.

Still another object is the provision of means and methods for uniformly abrading the surface of a moving rod with abrasive tape.

Another object is the provision of mechanism for drawing or reciprocating a portion of an abrasive tape back and forth across a rod to be finished and for feeding unused tape to the reciprocating portion.

Yet another object is the provision of mechanism for reciprocating a portion of an abrasive tape across the surface of a rod to be finished, and for feeding unused tape to the reciprocating portion to permit the finishing of moving rod in a substantially continuous process.

A still further object is the provision of novel draw die means for reducing the size of a rod.

These and other novel features and objects of the invention will become more readily apparent when considered in the light of the following description taken in connection with the accompanying drawings, wherein one embodiment of the invention is illustrated. It is to be expressly understood, however, that the drawings are employed for the purpose of illustration only, and are not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings, wherein similar reference characters refer to similar parts throughout the several views:

Fig. 1 is a schematic view indicating the arrangement of a rod finishing machine constructed in accordance with the principles of the present invention;

Fig. 2 is a top view, partially in section, showing in detail one of the several rod finishing units of the machine indicated in Fig. l.

Fig. 3 is an end view, partially in section of the mechanism shown in Fig. 2.

Fig. 4 is a view of the mechanism of Fig. 3 rotated bodily clockwise through an angle of 90 degrees; 4'

Fig. 5 is a view of the mechanism of Fig. 3 rotated clockwise 180 degrees;

Fig. 6 is a view of the mechanism of Fig. 3 rotated clockwise 270 degrees;

Fig. 7 is a partial sectional View, taken along line 7--7 of Fig. 3, of the tape feed mechanism;

Fig. 8 is a partial sectional view, taken along line 2,749,670 Patented June 12, 1956 ICC 2 8 8 of Fig. 3, showing a portion of the feed mechanism of Fig. 7;

Fig. 9 isla side elevational view, partially in section, of one of the bell cranks shown in Fig. 3;

Fig. l0 is an end View of the bell crank of Fig. 9;

Fig. ll is a view, partially in section, of the draw die mechanism shown in Fig. l;

Fig. l2 is a View in perspective of a rod straightener adapted to be usedin place of the draw die mechanism shown in Fig. 1l, and

Fig. 13 is a schematic view in perspective of a modification of the bell crank mechanism.

The machine includes in general a base 4 provided with a series of upright tubular members 5 Welded to the base and connected by longitudinal tubular members 6 and tubular cross members 7 Welded thereto. A slotted bracket 8 is mounted at the center of each cross member and similar slotted brackets 9 aligned therewith are mounted on members 5 at their upper ends. A circular support 10 is rotatably mounted in each set of slotted brackets and may be locked against rotation therein by set screws 11. Each support is provided with a central aperture 12 through which a work piece 13 may be threaded and moved longitudinally through the machine during the finishing operation.

The work piece or rod to be nished is carried by a supply reel 14 mounted on a suitable base 15, 4and is drawn continuously through the machine by a bull block reel 16 driven by a motor 17. In the event it is desired to form the finished rod into wire of different shape immediately following the nishing operation, the rod may be threaded directly from the above machine to a rolling mill, not shown, instead of being coiled on the reel 16, in which case the rolling mill would replace the bull block and draw the rod through the finishing machine.

The left end of the machine is provided with a draw die assembly 18, to be described more fully hereinafter, mounted on a cross bar 18a welded to the ends of frame members 6. Each of the supports 10 is provided witha pair of oscillatable bell cranks 19 and 20 rotatably mounted thereon and provided at their adjacent ends with tape actuating members or guide rolls 21 and 22. Abrasive tapes 23 pass over each set of guide rolls and around the rod to form U shaped loops. As will be described in detail hereinafter, means are provided for oscillating each pair of bell cranks to reciprocate the tape in the U shaped loop back and forth across the surface of the rod as well as means for guiding the tape, feeding unused tape to the loop portion thereof, and tensioning the tape in the loop between guide rolls 21 and Z2 to insure engagement of the abrasive surface of the tape with the surface of the rod.

In the embodiment illustrated there are twelve circular supports 10, and starting at the left end of the machine, each group of four supports forms a separate finishing section. The first section is provided with a relatively coarse abrasive tape, and a tape of finer grit is used in the succeeding sections in order to impart a fine finish to the rod. Since it is desirable to subject the entire circumference of the rod to the action of the abrasive tapes, the supports 10 are so positioned in each group that succeeding tape loops are spaced angularly apart from each other about the axis of the rod. Thus, in each group the first support would be positioned as in Fig. 3, the second as in Fig. 4, the third as in Fig. 5, and the fourth as in Fig. 6. As the loops are preferably so arranged that the tape at the closed end of the loop engages the surface of the rod through an arc of approximately it will be readily apparent that the tapes of each group will act abrasively on the entire circumference of the rod surface.

Although the machine as illustrated comprises twelve of the supports with the tape loops arranged as described, it has been found that in some cases as many as thirty-six of these supports spacedaxially along the rod may be used advantageously, depending on the type of rod being finished and the qualify of finish desired. In like manner, thesucceeding tape loops of each group may be arranged in groups of three with the loops spaced angularly 120 apart, in groups of six spaced angularly 60 apart, or in any other arrangement or combination of arrangements best suited to provide the desired quality of finish on the type of rod being finished, the arrangement being such that the supports can be rotated to any desired angular positions and locked by set screws 11.

In the operation of a machine of this typeit has been found desirable to have that portion of the rod which is acted on by the abrasive tape straight and under relatively high tension. To this end guiding means, to be described in detail hereinafter, are provided to position the rod against radial movement by the pull of the tapes acting thereon, and the rod as it is drawn from the reel 14 by the bull block is straightened, reduced in diameter, and placed under high tension due to its passage through the draw die assembly 18. Since the rod is guided against radial movement and is under high tension, that portion of the rod acted on by the tapes is straight and is abraded uniformly by the tapes to provide a smooth and polished surface finish substantially free from the surface imperfections and flaws which ordinarily characterize rod of commercial grade which has not been subjected to a finishing operation of this type.

Although the draw die assembly illustrated is particularly advantageous when used in connection with the production of highly finished wire from ordinary hot rolled steel rod, and in some cases from cold rolled rod and other types of rod, there are cases wherein itis desirable to abrasively finish the surface of a rod without passing it through a draw die to straighten the rod and reduce the cross sectional area, and in such cases the draw die assembly 18 may be replaced by any suitable rod tensioning or straightening device, such as a conventional roll type straightener assembly 24 as illustrated in Fig. 12. comprising a series of horizontal rolls 25 and a series of vertical rolls 26, the rolls being mounted on a bracket 27 adapted to be mounted on the cross member 18a.

The draw die assembly 18, which will be described in detail and which is shown more particularly in Fig. l1, has been found particularly advantageous in imparting a high quality finish directly to hot rolled steel rod and other relatively soft rod prior to further finishing operations on the rod, and in some cases the finish produced on the rod by the draw die assembly alone is satisfactory for the use for which the finished rod is intended. The fact that the adjacent draw dies are placed in close proximity to each other and the fact that the rod is passed from the first die through the second die without cooling theV rod is believed to be of considerable importance in producing a smooth finish, as the metal of the rod, which flows and is heated appreciably in passing through the first die, is, due to the close proximity of the dies, still in a plastic and heated state as it enters the succeeding die, thus resulting in a smooth flow of metal as the rod is further reduced in size in passing through the succeeding die.

Another advantage appears to be that with this die arrangement, work hardening of the rod is reduced to a minimum as compared to other multiple pass rod drawing operations, wherein the rod is permitted to cool or become stable, between passes, or the dies are separated a suicient distance to permit the metal of the rod to cool and reach a stable condition between passes. Another contributing factor appears to be the relatively low speed of the rod through the dies, as compared with the speed utilized in more conventional rod drawing operations. Speeds of the order of forty to fifty feet per minute have given very satisfactory results, although these speeds are not to be considered as lower and upper limits, as it is considered that higher speeds can be successfully used as well as speeds lower than forty feet per minute, the speed depending `to some extent on the characteristics of the rod being drawn, the amount of reduction by each die, and the number of adjacent succeeding dies utilized, it being noted Y that in the preferred form of the invention two such dies are utilized.

It is fundamental that if surface imperfections in the rod are to be removed, metal must be removed from the surface of the rod, and the elimination of severe work hardening achieved by the above described die arrangement permits the abrasive tapes to remove more metal in a given time or with a given number of tapes than would otherwise be the case. In this connection it has been found that the degree of work hardening present in rods whose diameter has been materially reduced through multiple die drawing in the conventional manner is such that the removal of metal from the surface by means of abrasive tape is more difiicult than with the present die arrangement.

Referring particularly to Fig. ll, a die box 28 is mounted on cross bar 18a by means of cap screws 29 as shown. The box is provided with upright partitions 30, 31 and 32 in which are mounted respectively draw dies 33 and 34 and felt washer 35, these being maintained in position by retaining washers 36, 37 and 38 and having their bores 39, 40 and 41 aligned with each other and with the rod apertures 12 in supports 1f). Bores 42, 43 and 44 in the partitions permit passage of the rod through the box, a similar bore 45 being provided in the cross bar 18a. The partitions'form lubricant reservoirs 46 and 47 interconnected by port 48 in partition 31, and if desired a supply of suitable lubricant such as grease may be maintained in the reservoirs above the level of the rod to lubricate the latter as it passes through the dies, the escape of lubricant around the entering rod being prevented by the felt washer 35 adapted to engage the rod as it enters the box. The bores 40 and 39 of the dies are so dimensioned that each die effects a reduction in the size of the rod 13 as it passes from the reel 14 through the box.

The mechanism for tensioning, guiding, reciprocating and feeding the abrasive tape is shown in detail particularly in Figs. 2, 3, 7 and 8. As shown in Fig. 3, a tape supply reel 49 is rotatably mounted on shaft 5t) carried by support 10, its rotation being frictionally retarded by washer 51, spring 52, washer 53, and nut 54, which serve to press the reel into engagement with boss 55 on support 10. From the reel the tape 23 passes through a brake mechanism 56.

This mechanism includes a pair of parallel flat links 57 provided with slots 58, and held together at their lower ends by a shaft 59 having a brake roller 60 rotatably mounted thereon and serving as a spacer for the links. The links are pressed into frictional engagement with the ends of the roller 60 by spring 61, washer 62 and nut 63 on the outer end of the shaft, the tension of the spring and the friction between the roller and links being varied by loosening or tightening of the nut. A second brake roller 64 is positioned between the links and provided with a shaft 65 extending from either end slidably and rotatably mounted in link slots 58. A stud 66 of rectangular cross section carried by support 10 passes through the slots at their upper ends and serves to loosely support the brake assembly against rotation thereon while permitting the assembly to move on and slide along the stud to maintain alignment with the abrasive tape,

The tape 23 passes from the supply reel under and around roll 60, between the rolls and around roll 64, and thence downward toward the bell crank 19. .Thus the tape is wrapped almost completely around brake roll 60, and a pull on that portion of the tape leading from roll 64 toward bell crank 19 will tend to force the latter roll against the tape between the rolls and insure that the tape will rotate the frictionally controlled roll 60 rather than slide over its surface. The spring 52 on the tape reel shaft is preferably so adjusted that the tape is only tensioned sufficiently to insure full engagement of the tape with lower brake roller 60, the main braking action being provided by the brake assembly 56. Thus the change in diameter of the roll of tape on the reel as the `tape is used up has very little effect on the total braking action exerted on the tape. j

The bell cranks 19 and 20, as shown more particularly in Figs. 9 and l0, comprise a pair of triangular side plate members 67 and 68 interconnected by a strut 69. Bell crank 19 is mounted for rotation on a shaft 70 extending between support 10 and auxiliary bracket 71 carried thereby and spaced therefrom. The left leg of the triangle forms an upwardly extending lever arm 72 having a connecting rod pin 73 extending between the two side plates at the upper end of the arm, while the lower leg forms a horizontal lever arm 74 having a shaft 75 extending between the side plates at the outer end of the arm. Flanged tape guide rollers 76 and 21 are rotatably mounted on shafts 70 and 7S respectively between the bell crank side plates.

Bell crank 20 is rotatably mounted on feed drive shaft 77, the latter being mounted for rotation in bracket 71 and support and extending through the latter, as best shown in Figs. 2 and 7. The right leg of the triangular bell crank forms an upwardly extending lever arm 73 having a connecting rod pin 78a extending between the two side plates, while the lower leg forms a horizontal lever arm 79 extending in opposed relationship to arm 74 and having flanged tape guide roll 22 rotatably mounted on a shaft 80 at its outer end adjacent roll 21, the relationship of the rolls preferably being such that an abrasive tape passing over rolls 76 and 21, around the rod, and over roll 22 as shown, will, when tensioned between the rolls 21 and 22, form a U shaped loop of tape having substantially parallel legs with the closed end of the loop engaging the rod through an arc of approximately 180 The connecting rod pins 73 and 78a are connected by a connecting rod 81, and it will be apparent that when one bell crank is rotated on its axis the other bell crank will rotate in the saine direction, but that the ends of lever arms 74 and '79 and the guide rolls 21 and 22, being in opposed relationship to each other, will move bodily in opposite directions relative to each other. Thus a tape tensioned between the rolls and around the rod will be reciprocated over the surface of the rod when the bell cranks are oscillated on their axes.

In the illustrated embodiment of the invention as shown in Figs. 2 and 3, such oscillation is eected by a motor 82 mounted on bracket 83 on the back side of support 10 and having a crankshaft 84 provided with a crankpin 85 connected with pin 78a on bell crank 20 by a connecting rod 86. Thus the connections are such that on rotation of the crankshaft by the motor the bell cranks will be oscillated simultaneously in the same direction about their axes and through substantially equal angles, while guide rolls 21 and 20 will oscillate bodily through substantially equal arcs to either side of the positions shown but in opposite directions.

Feed mechanism for the tape, as shown more particularly in Figs. 3, 7 and 9, includes a flanged feed roll 87 mounted on shaft 77 and driven thereby through pin 38. A second untianged feed roll 89 is mounted on a shaft 90 Vmounted for rotation in the upper end of a forked swinging bracket 91, the bracket being rotatably mounted at its lower end on a shaft 92 secured to support 10, and being maintained on the shaft by collar 93 held on the end of the shaft by pin 94. The roll 89 is driven by shaft 90 through a drive pin 95, and the shaft is driven through identical gears 96 and 97 keyed respectively to shafts 77 and 90, the teeth of the gears being so shaped and meshed as to permit the roller 89 to engage the surface of flanged roller 87. A spring 98 connected between a pin 99 on swinging bracket 91 and a pin 100 on bracket 71 serves to bias the bracket 91 in a counterclockwise direction about shaft 92 to urge roller 89 against roller 87. The shaft 77 is driven in a counterclockwise direction, as viewed in Fig. 3, by motor 82 through pulley 101, belt 102, pulley 103, reduction gear 104, shaft 105, and coupling 106. Although various gear ratios may be used in the gear reduction unit 104 to provide dilferent tape speeds, it has been found that tape speeds of 4 to 12" per minute have given satisfactory results and feed unused tape to the loop at rate sulcient to provide for efficient abrading action of the tape on the rod. In any case the feed speed is so chosen as to provide for the most efficient use of the tape for the type of work being finished.

As stated heretofore, that portion of rod 13 extending between die block 18 and bull block reel 16 is highly tensioned and straight, and in order to maintain this condition while the rod is acted on by the tape, rod guide rolls 107 and 108 are provided on each of the supports 10 and mounted on either side of the tape loop as shown particularly in Fig. 2. The rolls are provided with V-shaped grooves, roll 107 being mounted on a shaft 109 carried by brackets 110 and roll 108 being mounted on shaft 111 carried by brackets 112. The rolls are mounted directly below the rod in line with the tape loop, and consequently the tensioned loop of tape tends to maintain the rod in engagement with the rolls at all times, and at the same time tends to damp out any vibration of the tensioned rod which otherwise might occur. Any tendency of the tensioned tape to elfect radial movement of the rod is of course prevented by the guide rolls, and since all of the supports 10 have guide rolls similarly positioned with respect to the rod and tape loop and arranged to align the rod axially in the apertures 12 of supports 10, the rod is properly supported and aligned at each of the supports 10 regardless of their respective angular positions on the frame. The guide rolls can be positioned to align different size rods by motion of brackets and 112 bodily or by substitution of guide rolls of different size.

In the operation of the machine, the tape reel 49 having a supply of abrasive tape thereon with the abrasive side outward is placed on shaft 50. The tape is threaded through the brake 56 as heretofore described, down under rolls 76 and 21, around rod 13 and down around roll 22, under feed roll 87 and between that roll and roll 89, and from that roll to a suitable storage bin, not shown. The direction of movement of the used tape after leaving the roll 89 will of course depend on the angular position of support 10 on the frame, and auxiliary guide means such as roll 113 and trough 114 may be provided to guide the tape to a suitable bin in diiferent angular positions of the supports. As the tape is threaded through the mechanismas above described, it is preferably drawn tight by motion of the roll 89 out of engagement with feed roll 87 until the tape is tightened manually. The tapes for all of the supports 10 are of course similarly threaded and tightened.

Assuming that rod 13 has already been threaded through the machine and attached to bull block reel 16, the machine is now ready to operate. The motors 82 and 17 are started, and the rod is drawn through the die block and is acted on by the reciprocating tape loops associated with each of the supports 10. As soon as one coil of rod is nearly exhausted the end of another coil is welded to the trailing end of the first coil, the joint is ground down as needed, and the second coil is fed into the machine. Since large reels of tape can be used, the process is practically continuous, and long lengths of rod can be finished without stopping of the machine. It will also be understood that as the reels of tape become exhausted, the ends of other reels may be adhesively or otherwise secured to the trailing ends of the exhausted reels without interrupting the operation of the machine.

As stated above, tape feed speeds of the order of 4 to 12 per minute and rod speeds of forty to fifty feet per minute have proven satisfactory, but it is to be specically understood that other speeds may be used, the speeds chosen depending on the material being finished, the type and number of tapes used, and the quality of iinish desired.

With regard to tape reciprocation speed and the amplitude of reciprocation, crankshafts S4 have been driven at about 1750 R. P. M. with very satisfactory results, the tape of course completing one cycle of reciprocation with each revolution of the crankshaft. A crankarm radius of approximately 5/16 inch has been used satisfactorily, and since the lever arms of the bell cranks are all of the same length in the embodiment shown, the amplitude of tape reciprocation would be twice that amount, or Ss. Thus, during one cycle of operation, the tape will travel across the rod S; inch in one direction and the same distance in the other direction, cutting in both directions.

While it is recognized that due to the geometry of the bell crank arrangement, the free portion of the tape loop, that is, that portion of the loop between the lines of tangential engagement of the tape with guide rolls 21 and 22, may vary slightly in length during each cycle of tape reciprocation, this variation has been found to be so slight as to have no detrimental effect, particularly in view of the fact that the bell cranks oscillate through a very small arc and the feed mechanism takes up any slack in the loop. There appears to be a slight reduction and a corresponding slight increase in the tension of the tape in the loop every half cycle, due to the above action, but no adverse effects result with this action, and no diliiculty is experienced with tape breakage.` It is obvious that other mechanisms can be utilized soconstituted that no variation in tape length between the guides would occur during the cycle, but the simple mechanism illustrated has proved eicient and satisfactory for the purpose intended. In fact it is conceivable that a slight reduction in tape tension during each half cycle may be beneficial in allowing the tape to clear itself of used grit which has broken away from the tape during the abrading operation.

lt should be particularly noted that in the embodiment of the invention shown the only portion of the tape that reciprocates in that portion in the U-shaped loop. The tape passing over the guide and feed rolls to and from the loop moves at a rate governed by the gear ratio of the feed mechanism and in the same direction at all times without reciprocation, except for any slight variation in this movement which may be caused by the geometry of the mechanism as explained heretofore. Consequently the guide rolls and feed rolls do not oscillate about their axes in accordance with the reciprocation of the tape in the loop but substantially rotate in the same direction at all times at a rate determined by the feed mechanism. This is of course advantageous in minimizing inertia forces in the system at the relatively fast reciprocation speed employed.

In the embodiment of the invention illustrated the axes of guide rolls 21 and 22 are parallel and the tape passes over the wire at right angles to the axis thereof, but it will be readily apparent to those skilled in the art that if it is desired to effect greater tape contact area with the rod using the same width tape, the tape can be led over the rod at an angle to the axis thereof, in which case it would only be necessary to rearrange the bell crank shafts 70 and 77 at a different angle to each other rather than parallel as shown, and modify the linkage connecting the two bell cranks in order to insure simultaneous oscillation of the bell cranks about their axes to effect reciprocation of the loop portion of the tape.

There are numerous advantages inherent in the present invention, one of these being that the tape supply reel, being on a stationary part of the machine, can be mounted elsewhere if desired in order to permit the use of larger reels. Since only the loop portion of the tape reciprocates, the non-reciprocating portion of the tape may, by the use of suitable guides, be led from the supply to the loop in almost any desired path. The tape cuts in both directions of movement and is under substantially constant tension against the rod. The feed mechanism insures that the abrading eiiiciency of the tape in the cutting zone is substantially constant regardless of the length of the run, and the machine does not have to be continually adjusted to compensate for Wear of the abrasive element, as would be the case if grinding wheels were used. Even though the loop portion of the tape is reciprocated at high speed, it is not subjected to any detrimental jerking action, a fact which has permitted the use of paper tapes rather than cloth tapes in case of the finer grit tapes, an important factor in promoting economy of operation. Another advantage resides in the fact that the abrasive surface of the tape engages only one of the brake rolls and one of the feed rolls, a factor which materially reduces wear on the mechanism. If a polishing action only is desired in one portion of the machine, non-abrasive cloth tape can be substituted for the abrasive tape, and a suitable polishing compound applied to the tape as it passes through the machine. ln this case a very low rate of tape feed could be used, as wear of the tape material itself rather than the abrasive coating on the tape might be the determining factor. The various tape mechanism supports 1) can be quickly set and locked at any desired angles relative to each other to accommodate a particular type of work, and there are no complicated adjustments involved in the operation of the machine, practically the only adjustments required being the adjustment of the tape brake and adjustment of the positioning of the rod guide rolls to properly align dierent sizes of wire. While the machine is particularly adapted for the finishing of round hot rolled and cold rolled steel rods and other rods suitable for abrasive finishing, it will be apparent that rods of oval shape as well as other shapes can be satisfactorily finished, as well as tubular members, and long rods that have already been straightened and are put through the machine for the abrading operation only. The double draw die arrangement is also advantageous, particularly in connection with the finishing of hot rolled steel rod in a continuous operation, as the closely spaced draw dies straighten the rod and reduce it to the desired size while producing thereon a smooth and relatively soft surface particularly adapted for abrasive finishing. Although separate drive motors have been used as a matter of convenience on the supports lil, a common drive shaft may be provided if desired to drive all of the tape feed and reciprocating mechanisms, and other means than that shown may be utilized to move work pieces longitudinally through the machine.

While one embodiment of the invention has been illustrated and described in considerable detail, it is to be understood that the invention is not limited to the form shown, but may receive a variety of mechanical expressions as will readily appear to those skilled in the art. Reference will, therefore, be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

l. Mechanism for abrasively finishing the surface of a rod including a stationary support having an aperture adapted to receive a rod to be finished, a pair of abrasive tape actuating members movably mounted on the support and connected for simultaneous movement back and forth in opposite directions with respect to such rod, tape feed mechanism for continuously moving in the same direction, abrasive tape from a tape supply over one tape actuating member, over the surface of the rod, and over the other of said members, a tape brake to retard the movement of tape over said one member, over the rod, and over the other member by said feed mechanism and to tension a tape extending over such rod between said members,

and power means for moving said members back and forth and for operating said feed mechanism.

2. Mechanism for abrasively finishing the surface of a rod including a stationary support having an aperture adapted to receive a rod to be finished, a pair of tape actuating members movably mounted on the support and connected for simultaneous movement in opposite directions with respect to each other, tape feed mechanism for continuously moving in the same direction, abrasive tape from a tape supply over one member, over the surface of the rod, and over the other member, a ltape brake to retard the movement of tape over said one member, over the rod, and over the other member by said feed mechanism and to tension a tape extending over such rod between said members, and power means for moving said members back and forth and for operating said feed mechanism.

3. The mechanism set forth in claim 1 wherein a plurality of said supports, each provided with said brake, tape actuating members, and tape feed mechanism, are positioned in spaced apart relationship with their apertures in alignment to permit the passage of a rod to be finished therethrough, said supports being fixed in angularly related positions with respect to each other about such rod as to cause tapes extending over such rod between said members on said supports to abrade the surface of a rod passed therethrough over its entire circumference.

4. Mechanism for abrasively finishing the surface of a rod including a frame, a plurality of supports provided with rod receiving apertures and rotatably mounted in spaced relationship on said frame with said apertures in alignment, tape actuating means carried by each support including a pair of tape reciprocating members movably mounted on the support and connected for simultaneous movement back and forth in opposite directions with respect to a rod passed through said aperture, tape feed mechanism positioned and adapted to draw abrasive tape from a tape supply over one of said members, over the surface of a rod passed through said aperture, and over the other of said members, a tape brake positioned and adapted to retard the drawing of tape from a supply over said one member, over the surface of such rod, and over the other member by said feed mechanism, and to tension a tape extending over such rod between said members, means for locking each of said supports in a selected position of rotation about a rod passed through said aligned apertures, and power means for moving the tape reciprocating members on each support back and forth and for operating said feed mechanism.

S. The mechanism set forth in claim 1 wherein rod guides are provided on said support for guiding a rod through said aperture, said guides being so positioned as to prevent radial displacement of a rod passing through said aperture by the action of a tensioned tape extending over such rod between said tape actuating members.

6. The mechanism set forth in claim 1 wherein the abrasive tape actuating members are respectively positioned on opposite sides of the support aperture to cause a tensioned tape extending over a rod adapted to extend through said aperture and between said members to assume the form of a U-shaped loop with the closed end of the loop positioned in engagement with the surface of the rod.

7. Mechanism for abrasively finishing the surface of a rod including a stationary support having an aperture adapted to receive a rod to be finished, a pair of oscillatable levers rotatably mounted on the support and having tape guides on their outer ends, means connecting said levers for insuring simultaneous oscillation of said levers to effect simultaneous oscillation of said tape guides in opposite directions with respect to such rod, means for continuously moving in the same direction an abrasive tape from a tape supply over one of said guides, over such rod, and over the other guide at a predetermined rate, means for tensioning that portion of such tape extending be- 10 tween the guides against such rod, tape brake means for opposing the movement of tape from the tape supply over said guides by said moving means, and power means for oscillating said levers and for operating said moving means to draw tape from a supply, through said brake, and over said guides at said predetermined rate.

8. Mechanism for drawing a U-shaped loop of abrasive tape back and forth across the surface of a rod while supplying unused tape from a supply to one leg of the loop and removing used tape from the other leg of the loop at a predetermined rate, comprising a support, rod guiding means, a pair of movable tape actuating guides mounted on the support and positioned to each engage one leg of a U-shaped loop of tape extending therebetween around the rod, means for moving said tape guides simultaneously to alternately shorten and lengthen one leg of the loop and to alternately lengthen and shorten the other leg of the loop by substantially the same amount, tape feed mechanism for continuously removing used tape from one leg of the loop at a predetermined rate, and tape brake means for opposing the movement of unused tape from a supply to the other leg of said loop by said feed mechanism.

9. Mechanism for drawing a U-shaped loop of abrasive tape back and forth across the surface of a rod while supplying unused tape to one leg of the leg and removing used tape from the other leg of the loop at a predetermined rate, comprising a support, rod guiding means, a pair of movable tape actuating guides mounted on the support and positioned to each engage one leg of a U- shaped loop of tape extending therebetween around the rod, tape brake means on the support adjacent one of said tape actuating guides adapted to engage and retard the movement of a tape extending from one leg of said loop over said one tape guide, tape feed mechanism on the support adjacent the other of said tape guides adapted to engage a tapeextending from the other leg of said loop over the other of said tape guides and to continuously move tape from said loop over said other tape guide at a predetermined rate, and means including a connection between the tape guides for moving said tape guides to draw the tape in the loop back and forth across the rod during said continuous movement of the tape, while maintaining the length of the loop between the tape guides substantially constant.

10. In an abrasive tape rod finishing machine having a iixed support, tape reciprocating, feeding and tensioning means including a pair of movable tape reciprocating guides mounted on the support, tape feed means on the support for continuously moving tape from a supply over said tape guides at a predetermined rate and in the same direction, tape brake means on the support for operating the movement of tape over said guides by said feeding means, and means for moving said tape guides simultaneously to effect reciprocation of a portion only of a tape extending therebetween during said continuous movement of the tape while maintaining the length of such tape portion substantially constant.

l1. A machine for finishing the surface of a rod with abrasive tape including means adapted to position a rod along an axis of the machine, a support on the machine, a pair of oscillatable levers mounted on the support with their axes parallel to and spaced radially outward from said axis, tape guides on the free ends of said levers, a connection between the levers for insuring simultaneous oscillation thereof, a tape brake on the support adapted to retard the movement of tape therethrough, a tape feed mechanism, means for operating said continuously feed mechanism to feed tape in one direction only at a predetermined rate, and means for oscillating said levers, said feed mechanism being positioned and adapted to continuously draw tape from a tape supply through said brake, over one of said tape guides, across the surface of a rod positioned along said axis and over the other of said guides, and said guides being positioned and 11 adapted to draw that portion of a tape extending therebetween back and forth across the surface of the rod.

12. A machine for linishing the surface of a rod with abrasive tape including means adapted to position a rod along an axis of the machine, a support on the machine, a pair of oscillatable levers mounted on the support having spaced axes parallel to said machine axis and lever arms in opposed relationship with the free ends adjacent to and on opposite sides of a plane through said machine axis, a tape guide on the free end of each lever, a tape brake on the support for retarding the movement of a tape therethrough, tape feed mechanism on the support for feeding a tape, means for operating said mechanism to continuously feed tape in one direction at a predetermined rate, and means for oscillating said levers and guides simultaneously to move that portion of a tape extending between said guides back and forth across the surface of a rod positioned along said axis, said feed mechanism being positioned and adapted to continuously draw tape at said predetermined rate from a tape supply o through said brake, over one of said oscillating guides, and over the rod and said other oscillating guide.

13. A machine as set forth in claim wherein a plurality of said supports with their associated mechanism are spaced apart along said machine axis and angularly thereabout with respect to each other, whereby tapes extending between the tape guides of each support and across the rod surface each act on a different portion of the surface of a rod passed through the machine along said machine axis.

14, A machine as set forth in claim 10 having a plurality of said supports with their associated mechanism spaced apart along said machine axis and mounted for rotation about said axis, and means for locking each of said supports in a selected position of rotation about said axls.

15. Mechanism for abrasively finishing the surface of a rod including means adapted to position a rod along a fixed axis of the mechanism, a support, apair of bell cranks rotatably mounted on shafts on said support having one pair of lever arms in opposed relationship with the outer ends thereof adjacent each other and spaced radially outward from said axis and the other pair of arms extending substantially at right angles to the first pair of arms and in the same direction therefrom, a connecting rod connecting said second pair of arms, tape guide rolls rotatably mounted at the adjacent ends of the first named pair of arms, a tape feed roll mounted on one of said shafts for rotation therewith, a second feed roll geared to the lirst named feed roll and mounted on a support for bodily movement into engagement with the tirst named feed roll, means for biasing said second feed roll into engagement with the first named feed roll, a tape guide roll rotatably mounted on the other bell crank shaft, means for driving said feed rolls to feed abrasive tape therebetween in one direction at a predetermined rate, a tape brake on the support adjacent the last named guide roll adapted to receive an abrasive tape from a supply and to retard the movement of tape through the brake, and means having a connection with said bell cranks for effecting oscillation thereof on said shafts, said tape feed rolls being so aligned with respect to said brake and all of said guide rolls as to be adapted to draw tape from a tape supply through said brake and over said guide rolls with the portion of said tape extending between the rolls on the adjacent ends of said bell cranks engaging a rod positioned along said axis.

16. Tape actuating and feeding mechanism for an abrasive tape finishing machine including a support, a first lever rotatably mounted on the support, a first tape guide having a tape guiding surface concentric with the axis of rotation of said rst lever, a first tape actuating guide on the outer end of the lever, a second lever rotatably mounted on Vthe support, a second tape actuating guide bn the end thereof, a second tape guide having a guiding surface concentric with the axis of rotation of said second lever, a tape brake on the support adjacent the first tape guide adapted to receive abrasive tape from a tape supply and to retard the movement of tape through the brake, means for drawing tape from a supply through said brake and over said guides in the order named at a predetermined rate, and means connected to said levers for effecting simultaneous oscillation thereof about their axes to actuate a tape extending between said lirst and second tape actuating guides back and forth across a work piece.

17. Mechanism for finishing the surface of a work piece with abrasive tape including a support, a tape tensioning device mounted on the support and adapted to receive abrasive tape from a tape supply, tape feed mechanism mounted on the support spaced from said tensioning device and adapted to draw tape therethrough at a predetermined rate, and means for actuating a portion of a tape extending between said tensioning device and feed mechanism to move said portion back and forth across a work piece including a pair of spaced tape actuating guides movably mounted on the support and positioned to engage a tape extending between said tensioning device and feed mechanism at spaced apart points on a tape extending between said tensioning device and feed mechanism, and means connected with said guides for effecting simultaneous movement thereof to effect said back and forth movement of a tape extending therebetween.

18. Mechanism for finishing the surface of a work piece with abrasive tape including a support, a pair of spaced apart tape guides on the support, an abrasive tape extending from a tape supply over said guides, means associated with said guides for tensioning that portion of the tape extending therebetween and for continuously moving said tape over said guides in the same direction from said supply at a predetermined rate, and means for actuating a portion only of said tensioned tape during said continuous movement of said tape to move it back and forth across a work piece including a pair of spaced apart tage actuating guides movably mounted on the support and positioned in engagement with said tensioned tape, and means connected with said tape actuating guides for effecting simultaneous movement thereof in opposite directions.

19. Mechanism for abrasively finishing the surface of a rod including a stationary support having an aperture adapted to receive a rod to be finished, a pair of abrasive tape actuating members movably mounted on the support and connected for simultaneous movement back and forth in opposite directions with respect to said roti, tape feed mechanism mounted on said support adapted fory engaging and movingan abrasive tape from a tape supply at a predetermined rate and in the same direction over one tape actuating member, over the surface of a rod positioned in said aperture, and over the other of said members, a tape brake mounted on said support for engaging and retarding the movement of a tape from a supply over said one member, the surface of a rod positioned in said aperture and said other member by the operation of said tape feed mechanism, said brake being operable to tension a tape extending between said actuating members, and power means for moving said members back and forth and for operating said feed mechanism.

References Cited in the file of this patent UNITED STATES PATENTS 165,977 Beers July 27, 1875 208,341 Smith Sept. 24, 1878 2,033,392 Pallas Mar. 10, 1936 2,109,312 Dimmick Feb. 22, 1938 2,165,616 Cox J'uly ll, i939 2,188,470 i Brandt Ian. 30, 1940 2,284,904 Illmer et al. June 2, 1942 2,329,376 Illmer et al. Sept. 14, 1943

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