US3031724A - Top roll guides - Google Patents

Description

y 1962 R. K. BUTLER 3,031,724

TOP ROLL GUIDES Filed y 1 1960 2 Sheets-Sheet 1 R. K. BUTLER TOP ROLL GUIDES May 1, 1962 2 Sheets-Sheet 2 Filed May 31, 1960 3&31324 Fatented May 1, 19%.?

3,ti31,724 TGP RGLL GUIDES Richard K. Butler, Whitman, Masa, assignor to Machinecraft, Ina, Whitman, Mass, in corporation of Massachusetts Filed May 31, 196%, Ser. No. 32,741 Qiaims. (Cl. 19-253) This invention relates to spinning and roving frames and is an improvement in the devices used to hold the top drawing rolls of such frames in working relation with their opposing bottom rolls so that they may perform their function of reducing or drawing the strands of textile fibers down to their final size in the making of yarns.

In particular, the invention is an improvement in the top roll guiding, positioning and weighting devices of Cotchett and Butler Patent No. 2,865,057, granted December 23, 1958, and in addition provides novel means for guiding the aprons used on the middle pair of the three cooperating pairs of drawing rolls for attaining long draft of the strands.

When the improved top roll guiding, positioning and weighting devices of such patent are used on roll stands which mount the drawing rolls at an increased distance outwardly away from the creel and tilt the drafting plane defined by these rolls up at a much steeper angle than heretofore, so as to get more creel space for larger supply bobbins, and in certain other instances as well, the roll weighting does not always remain constant. The forked rear end-portion or yoke of the top arm which guides the front top roll does not always settle down or stay down in intended manner on the auxiliary back bar or stud over which it is hooked. This is because of the greater tendency of the top rolls and their guiding, positioning and weighting devices to gravitate down the steeper slope of the drafting plane, and when this component of the weight of these parts is added to the inherent downhill drag exerted on these parts by the bottom rolls in driving the top rolls and their aprons, the increased burden of the yoke against the auxiliary back bar or stud creates enough friction between the rear legs of the yoke and the rear surface of the stud to interfere with the intended free sliding of these surfaces over each other.

This retarding friction reduces the effective pressure transmitted to the middle and back top rolls by their proper guide arm, to which the loading of the top rolls by the roll weighting means is delivered by the upper roll guide or top arm. The same forces of gravity and drag tend to carry this under guide arm of the middle and back top rolls downhill, creating a similar retarding friction on the back of the slots of the yoke which mounts this guide arm on the stud. This friction, like the sticking of the top arms yoke, reduces the effective pressure transmitted to the back top rolls, which weakens the holding power of the back rolls, with consequent variations in the feed of the fibers of the strand being drawn. This unequal feed lowers the quality of the resulting yarn, by causing variations in the strength thereof.

To eliminate this occasional sticking of the guide arms on the studs :on which they are mounted, the present invention provides a pivoted link to connect the under guide, carrying the middle and back top rolls, with the auxiliary back bar or stud, and detaches the upper arm, which guides the front top roll and weights the under arm, entirely from the stud, converting it into a saddle. The

pivoted link gives a double-jointed mounting to the entire roll guiding structure which is free from any frictional resistance to the settling of the guide arm and saddle, so that the entire weighting force applied to the saddle is delivered to the top rolls and is exerted thereby on the strand being drawn.

The structure of prior Patent No. 2,865,057 also left room for improvement in that when the outside diameter of the cots of the back top roll became reduced by buffing, this lowered the axis of the back top roll, and the consequent attempt of the under guide arm to settle at the point where it is supported by the back top roll was resisted by the inelastic bottom apron. The under guide arm holding the middle and back top rolls had to rock about a center well above the axis of the middle bottom apron roll in order to settle down, which it could not do freely because this required a forward movement of the tensor which keeps the bottom apron tight. Such movement was strongly resisted by the inextensible bottom apron, causing the tensor to react on the under guide arm, the tensor being rigidly mounted thereon, by

holding up the rear end of the arm and urging the arm rearward. This action diminished the weighting and consequent grip of the back top roll on the fibers, both directly and through interfering with the described free sliding of the yoke on the auxiliary back bar or stud through increasing the friction therebetween. This situation was found to arise even in spinning frames having the conventional slope of the drafting plane of around 30 to the horizontal, and where no increase of the gravitational force of the parts was involved.

The novel structure using the described link mounting of the guide arm of the middle and back top rolls and the saddle for the front top roll detached from theauxiliary back bar, remedies this situation also. It also eliminates the occasional catching of the roving in the legs of the prior yoke, when the roving bobbin over-run and slaoken the roving.

Improved apron-guiding and tensioning devices are provided herein which eliminate the usual. cradles riding on the rotating necks and journals of the middle rolls,

being mounted instead on operatively fixed and non-rotating parts, thus saving wear, and which provide for quick and easy removal and replacement of the aprons and of the guiding, positioning and weighting means for the middle and back top rolls, and for adjusting the elevation of the nose or delivery ends of the aprons with respect to the nip of the succeeding front rolls.

Novel and simplified means is provided for varying the ratio or distribution of the weighting applied to the respective top rolls, which avoids the possible loss of adjustment of the setting or spacing of the middle toproll with respect to the back and front top rolls in the patented structure of Patent No. 2,865,057 and in other devices, in changing the relative weighting, and vice versa in changing the spacing.

Other aims of the invention, and the mannerof their attainment, are as set forth hereinafter.

An illustrative embodiment of the invention is shown in the accompanying drawings, in which:

FIG. 1 is a vertical transverse section through the top and bottom rolls of a spinning frame.

FIG. 2 shows the rear portion of the novel guiding, positioning and weighting means for the middle and back top rolls of FIG. 1.

FIG. 3 shows the forward portion of the novel, guiding, positioning and weighting means of FIG. 1.

FIG. 4 is a section on line 4--4 of FIG. 1.

FIG. 5 is a section on line 5-5 of FIG. 1.

FIG. 6 is a section on line 66 of FIG. 1.

FIG. 7 is an end view of the apron-bearing top and bottom middle rolls, showing the improved edge-guiding and tensioning means for the aprons.

FIG. 8 is a perspective view of the edge-guides shown in FIG. 7.

FIG. 9 is a front view of one boss each of the top and bottom rolls of FIG. 7, looking in the direction of the arrow A of the latter, with the aprons shown in section.

FIG. is a perspective view of the bottom tensor of FIGS. 7 and 9, with the tensor of FIG. 8 in place there- The invention is shown applied to a spinning frame in which the roll stand 1 and the drafting plane defined by the hips of the three opposed pairs of drawing rolls are disposed at the conventional angle to the horizontal. As usual, the three bottom rolls 3, '5 and 7 are mounted in bearings 9, 11 and 13 and are fixed but adjustable toward and from each other by means of cap screws 15 put through a slot 17 extending lengthwise of the roll stand 1. The usual back bar 19 paralleling the bottom rolls and guiding the roving into the nip of the back rolls is atfixed to the stand 21, which is mounted on roll stand 1 by cap screw 23 put through the slot 17, the back bar thus forming a fixed abutment.

The novel means for guiding, positioning and weighting the middle and back top rolls comprises a member 25, FIGS. 1 and 3, of inverted U-section having a hub 27 at its forward end in which the middle top roll is permanently mounted. The hub 27 fits tightly about a sleeve 2? bushed at both ends with low frictional material and in which the shaft 31 of this middle top roll 33 rotates freely. Preferably this roll is of the type shown in Cotchett Patent No. 2,937,414, granted May 24, 1960, and comprises two bosses, preferably knurled, screwed tightly onto the reduced and threaded end portions of shaft 31, so that they and the shaft turn as a unit. The sleeve 23 is fixed against endwise and turning movement in hub 27, as by a pin 35 driven through a passage 37 intersecting the bore of hub 27 and entering a matching groove in the surface of sleeve 29 at mid-length thereof. Thus member 25 is the immediate means for guiding, positioning and weighting the middle top roll. It is preferably molded of nylon, Delrin, or other plastic of high modulus of elasticity, for ease of manufacture, and herein is press fitted onto sleeve 29.

Member 25 fits as shown in FIG. 6 between the downturned lateral flanges of a member 46:, FIGS. 1 and 2, also of inverted U-section, being fixed therein with capacity for longitudinal adjustment by means of a bolt 41 and nut 43, the bolt extending through a longitudinal slot 45 in member 25 and a slot '47 in the part 44 It also goes through a member 39, to be described. A spaced 46 within the slot 45 keeps member 25 from being clamped at this point to the member 40. A second bolt 49 with nut 51 extends through a slot 53 in the rear end of member 25 and through a hole 55 in member 40 to clamp the parts 40 and 25 together.

The member 4t) has deep lateral flanges 57 at its rearward end, between which is mounted a third member 59 of inverted U-section termed for convenience the link. This link swings freely within the flanges 57 of member 40 about a transversely extending pivot pin 61, FIG. 5, permanently fixed in holes 62 in flanges 57 and passing freely through holes therefor in the flanges 63 of the link.

A pin 65 of large diameter fits freely within appropriate holes in the rear end of flanges 63 of link 59, and extends slidably through a sleeve 67, FIG. 4, fixed in parallel relation'to back bar 19 between the upper ends of the two elements of a clamp 69 fixed on back bar 19 by bolt 71 and nut, the bolt passing through these elements. Sleeve 67 is of a length to fit closely but freely between the flanges 63 of link 59, and pin 65 fits closely but freely within both the sleeve 67 and the holes formed for its ends in flanges 63, thus forming a pivot in fixed position for the link.

Thus, so long as the link is in the position shown in the drawings, the flanges 57 of the outer member 40 overlap the ends of the pin (-FIG. 4) and prevent its escape, but when the member 40 is lifted and the flanges 57 thus raised, the pin may he slipped out from the sleeve 67 and the flanges 63 and the parts 25, 4i) and 59 comprising the top arm removed as a unit, along with the middle and back top rolls.

The back top roll 73 is detachably mounted by means of its neck in semi-circular notches 75 formed precisely opposite each other in the depending lateral flanges of rear member 40 of the top arm, to receive and fit accurately into grooves at equal distances from the midpoint in the length of a bushed sleeve 77 similar to the sleeve 29 of the middle top roll 33, described. Like the middle top roll, the rear top roll 73 comprises cot-covered bosses screwed tightly on to the reduced and threaded end portions of shaft 7 9, which rotates freely within the hushed sleeve 77. A leaf spring 81 secured between the nut 43 of bolt 41 and the spacer 46 holds the neck or sleeve within the notches 75 and thus keeps the roll in place on the top arm when the latter is tipped up to clear the rolls of lint and lap-ups.

Thus the top arm and the two rolls held thereby are constrained to move solely along a plane perpendicular to the bottom rolls, the top arm being held in strict rightangle relation to the fixed axis defined by pin 65, and each top roll is held strictly parallel to its opposing bottom roll.

The front top roll 85, preferably of anti-friction (ball bearing) construction, has its individual guiding, positioning and weighting member 37. The depressed front end portion thereof is shaped to provide a semi-cylindrical cavity 89 which receives the reduced mid-length portion of the sleeve or spacer 91 which spaces apart the two bosses which turn freely on shaft 93. The spacer is of reduced diameter where engaged by the member 87, to provide shoulders to stand at each lateral end of the semicylindrical cavity 89 to hold the roll against endwise movement therein.

This portion of member 87 is ribbed along its outer surface, to stiffen it against distortion under the load of the Weighting devices.

A hook 95 is affixed to the rearwardly extending straight portion of member 87 with capacity for longitudinal adjustment thereupon, by means of a cap screw 97 (with washer) put through a slot 99 and threaded into the rectangular base portion of the hook which fills the space between the two downturned lateral flanges of the U-section rearward portion of member 87. This hook is engaged by stirrup 101 of the roll-weighting mechanism (not shown), which may be of any usual or preferred construction. The weighting thus applied is transmitted in part to the front top roll by the front portion of member 87, and for the remainder by the rear portion of such member to the top arm holding the middle and back top rolls, by the cradle 39, FIGS. 1 and 6, fixed on the top of member 43 of the top arm by bolt 41 which as stated passes through longitudinal slot 45 of member 25 and also through slot 47 of member 4%. The member 87 is provided with a yoke 1%, FIG. 6, alfixed by a bolt 105 put through a longitudinal slot in the member 87 into a nut 109, the yoke having fixed in its ends a transverse pin 13.1 which rests in a slot extending across the cradle 39. Thus articulated from the top arm composed of parts 25 and 49, a part of the weighting applied by stirrup 101 to the saddle member 87 is transmitted through cradle 39 to the top arm to weight the middle and back top rolls. Preferably the cradle 39 is made of nylon or other durable plastic, and has an extension on its bottom surface fitting and filling the width of slot 47 in member 40. This interengagement of pin 111 and the slot keeps the saddle member 87 in alignment with the roll guide 25, 40, thus preventing the front top rolls axis from getting out of parallel with the bottom rolls axis. Such departure from parallel relation occurs in prior types of capbarless roll-guiding systems, and results in a swinging of the front top roll in an are, commonly termed pendulum action or hunting, and causes bad yarn because the grip of the front rolls on the fibers varies as the top roll swings into and out of parallel, causing the fibers to be drawn forward in non-uniform amounts.

In distributing the weight between the three lines of top rolls, movement of the hook along the saddle memher 87 determines the proportion of the total loading applied to the front roll. Shift of cradle 39 determines the ratio of Weight distribution between the middle and back top rolls.

By this provision for full and independent adjustability of both the setting or spacing and the weighting of the three successive pairs of rolls, any desired ratio of weighting is attainable irrespective of the roll settings, and vice versa. Further, the spacing of the middle top roll from the back top roll is maintained unchanged by bolt 49 while bolt 41 is loosened in the course of varying the distribution of the weighting between the front top roll and the other two top rolls. This simplifies an operation which was considerably more diflicult in the device of the patent.

The double-jointed connection of the top arm through pivoted link 59 to its fixed point of support on the sleeve 67 fast to the back bar 19, cures any tendency such as found in the said prior structure for the rear end of the top arm to resist settling down properly so as to deliver the full intended share of the weighting to the back top roll 73. This is true equally well when the drafting plane is tipped up to 60 or more. Reduction in diam eter of the back top roll through bufiing now has no eliect on the weighting, because of the location of the front pivot 61 of the link 59 below the plane joining the forward edge of the bottom tensor 115 with the axis of the other pivot 65. Downward movement of pivot 61 occurs as the back top roll 73 gets smaller. This shortens the distance between the tensor and the back pivot 65, and the guide arm 4t? and its two top rolls move rearwardly to an extent permitting the bottom tensor and the nose of its apron M9 to swing about the axis of the bottom roll 5. Since this causes no increase in the tension of the bottom apron, the back top roll gets its full share of the weighting, and holds the fibers properly. The rear end of the top arm is freed from any friction or forces tending to resist its movement at right angles to the drafting plane.

The improved apron-guiding and tensioning devices comprise the tensors M3, 115, FIGS. 1, 7 and 9, removably mounted in open-ended slots 117 in the front edges of two brackets 11% press-fitted on the sleeve 29 of the middle top roll 33. Each tensor has notches such as indicated at 121, as illustrated in regard to the bottom tensor 115 in FIG. 10, to engage the brackets 119 and prevent endwise movement. The bottom tensor is out way at to clear the stirrup M1. The top tensor 113 has its ends flush with the ends of the bosses of the top roll. The bottom tensor 115 is longer than the top roll, and has in its ends-slots or holes 123 spaced apart by an interval substantially equal to the length of the top tensor 113. Through these slots are placed edge guides 125 of sickle shape, FIGS. 7, 8, 9, and 10, of which the blade portion 127 overlaps and engages the lateral edge of the lower or return run of the apron 129 on the bottom middle roll 131. The upper portion 133 extending rearward at right angles to the blade overlaps and engages the edges of the upper or working run of bottom apron 129 and of the lower or Working run of apron 135 on the top middle roll 33. This portion 133 also adds to the weight of the edge guide 125 to resist its working up out of the slot 123, in which it rests loosely. Hole 137 onables it to be easily removed from the slot in the tensor by inserting a nail or other pointed instrument therein and liiitng it out.

With the inward edges of the upper and lower aprons at each end of the top roll 33 guided by the brackets 119, and the outward edges guided by the guides 125, deviation in either direction and resulting escape or damage to the aprons is prevented. Yet quick and easy removal of the aprons from the top roll and from the bosses of the bottom roll is effected by removing the two edge-guides 125 and working and sliding the aprons ofi' endwise from the bosses of both rolls.

When it is desired to separate the top rolls from the bottom rolls, as for purposes of clearing the rolls of lint and lap-ups, or for their removal for bufiing or replacement, the stirrup 161 is unwei hted and disconnected from the hook 95, whereupon the saddle 87 is lifted off with the top roll in place therein, being retained by leaf spring 139, attached to member 87 by bolt 97. The rear end of the top arm is then lifted as permitted by link 59, which movement draws the middle top roll 33 rearward, carrying with it the brackets ll) and the tensors 1 .13, 115. This slackens the bottom aprons 129, enabling the bottom tensor E5 to be moved forwardly out of its notches 117 in brackets 119 and then withdrawn endwisc out of the two bottom aprons i29. This leaves the bottom aprons completely free from all connection with the top arm and its parts, so that the front end of the top arm can be swung up and backwardly.

After it has passed the horizontal the rear end is lowered so that the sloping rear end 14 descends behind the head of bolt 71 in the clamp 69. Further settling of the link 59 as the attendant lets go of the top arm carrice the whole top arm forward, hooking the edge of portion 14 under the head of the bolt '71, so that the top arm with both rolls in place is held in upwardly and forwardly inclined relation well above the bottom rolls.

The structure provides for adjusting the tension of the bottom apron l2? and for taking up any slack arising therein through stretching after considerable use, and thus enables its working upper arm to be kept flat and so to retain its full control on the fiber being drawn from between the two aprons by the front rolls. Shift of the forward portion 25 frontward with respect to portion 48, after loosening bolt 49, advances the bottom tensor to take up the slack in the bottom apron 129.

The two-part clamp 69 for the auxiliary top arm mounting sleeve 67 enables the new structure to be applied directly to the usual back bar 19 of existing spinning frames, requiring merely the removal of the usual cap bars therefrom. In the said prior patent, special sectional back bars had to be provided.

A clearer roll 141 covered with felt is mounted by its neck 143 within the bight of a hook 1.45 pivoted in a bracket 147 fixed on the saddle 87, and rolls on the bosses of front top roll 35.

While I have illustrated and described a certain form in which the invention may be embodied, I am aware that many modifications may be made therein by any person skilled in the art, without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to the particular form shown, or to the details of construction thereof, but whatI do claim is:

1. Apparatus for drafting textile fibers including opposed pairs of top and bottom drawing rolls, the top drawing rolls each having two bosses and an intervening neck, means defining a fixed axis parallel to the axes of the bottom rolls, a roll guide resting on the necks of the middle and back top rolls and holding these top rolls in place on the bottom rolls by their necks alone, and means freely pivotally connected to the means defining the said fixed axis and pivotally connected to such guide at a point between such fixed axis and the back top roll and holding the roll guide in right-angle relation to the axes of the bottom rolls.

2. Apparatus for drafting textile fibers including bottom drawing rolls, top drawing rolls each having two bosses and an intervening neck, weighting means, means defining a fixed axis parallel to the axes of the bottom rolls, a roll guide engaging the necks of the middle and back top rolls and forming the sole means guiding, positioning and transmitting weighting pressure to such top rolls, a second roll guide weighting the front top roll and the first roll guide and positioned by the latter, and a link pivotally connected directly to the first roll guide and to the means defining the fixed axis and holding the first 7 roll guide in right-angle relation to the axes of the bottom rolls.

3. Apparatus for drafting textile fibers including bottom drawing rolls, top drawing rolls each having two bosses and an intervening neck, means defining a fixed axis parallel to the axes of the bottom rolls, a roll guide rigidly engaging the necks of the middle and back top rolls and positioning these top rolls on the bottom rolls by their necks alone, means freely pivotally connected to the means defining the said fixed axis and pivotally connected to such roll guide and holding the latter in right-angle relation to the fixed axis, a second roll guide for the front top roll resting on the first guide, and weighting means applying pressure to the second roll guide and through it to the first roll guide.

4. Apparatus for drafting textile fibers including bottom drawing rolls, top drawing rolls each having two bosses and an intervening neck, an apron around a bottom roll, a roll guide positioning a top roll on such bottom roll by its neck alone, a tensor for such apron on the roll guide, means defining a fixed axis parallel to the axes of the bottom rolls, a link pivoting about such fixed axis, and means pivotally connecting the roll guide and the link on an axis below the plane defined by the tensor and the fixed axis.

5. Apparatus for drafting textile fibers including bottom drawing rolls, top drawing rolls each having two bosses and an intervenin neck, a rigid member positioning the middle and back top rolls on the bottom rolls by their necks alone, a second member in articulated connection with the first member and holding the front top roll in place, an apron around the middle bottom roll, means defining a fixed axis in parallel relation to the bottom rolls, a tensor for the apron on the rigid first-named member, a link pivoting about the fixed axis and pivotally connected to the rigid first-named member at a point below the plane defined by the fixed axis and the apron-engaging edge of the tensor, and means applying pressure to the second member and through the latter to the first member to weight the rolls.

6. Apparatus for drafting textile fibers including bottom drawing rolls, top drawing rolls each having a neck, a roll guide rigidly engaging the necks of the middle and back top rolls and thereby positioning the latter in Working relation to the bottom rolls, aprons on top and bottom rolls, tensors for the aprons fixed on the roll guide, a fixed abutment, and means pivotally connecting the roll guide to the abutment with capacity for movement solely along a plane perpendicular to the bottom rolls but in all directions along such plane.

7. Apparatus for drafting textile fibers including bottom drawing rolls, top drawing rolls each having a neck, a roll guide holding the middle and back top rolls in operatively fixed relation to each other and in working relation with the middle and back bottom rolls respectively by engagement with their necks alone, a fixed abutment, a link pivotally connected to the roll guide and hinged on the abutment, and a saddle mounted on and positioned by the roll guide and holding the front top roll in working relation with the front bottom roll by its neck alone.

8. The combination according to claim 7 in which weighting'means load the saddle and the saddle in turn loads the roll guide and the middle and back top rolls.

9. Apparatus for drafting textile fibers having in combination top and bottom drawing rolls, aprons around the rolls, the top drawing roll having rotating parts and a stationary element, guiding, positioning and weighting means for the top roll, apron guiding and tensioning means fixed on such stationary element of the top roll including tensors within the aprons, one of such tensors having an aperture in an end-portion which end-portion extends outwardly beyond the edge of an apron, and an edge guide for such apron removably positioned in such aperture and preventing deviation of the apron beyond the end of the tensor.

10. Apron guiding and tensioning means for long-draft spinning and roving frames having in combination top and bottom drawing rolls, aprons thereon, guiding, positioning and weighting means for the top roll, tensors on the guiding, positioning and weighting means, one of such tensors having holes in its end-portions outside of the normal paths of the aprons, and edge-guides held in such holes adapted to engage the outward edges of the aprons to prevent deviation of the aprons.

11. In a spinning or roving frame having top and bottom drawing rolls and aprons thereon, in combination, means guiding, positioning and weighting the top roll, tensors within the aprons and mounted on the said means, one of such tensors having slots located beyond the outward edges of the aprons, and edge-guides for such edges removably mounted in such slots.

12. The combination according to claim 11 in which the edge-guides in one tensor overlap the ends of the other tensor.

13. The combination according to claim 11 in which the edge-guides overlap both runs of each bottom roll apron and the lower run of each top roll apron.

14. A tensor for the aprons of a long-draft spinning frame comprising in combination a flat bar to engage the interior surfaces of the aprons and apply tension to the latter, the bar having transversely elongated holes in its end-portions, and edge-guides to engage and guide the lateral edges of the aprons and slidably and removably mounted in the elongated holes in the tensor.

15. Apparatus for drafting textile fibers including bottom drawing rolls, top drawing rolls each having a neck, a fixed abutment, a roll guide hinged on the abutment and rigidly engaging the necks of the middle and back top rolls and thereby positioning the latter in parallel relation with the middle and back bottom rolls, weighting means, a saddle weighted thereby and overlapping the rol guide and guiding, positioning and Weighting the front top roll, the roll guide having a socket defining an axis extending parallel to the middle and back top rolls, and a pin fixed on the saddle in parallel relation to the front top rolls axis and resting in the socket and held thereby in parallel relation to the middle and back top rolls and weighting the roll guide.

References Cited in the file of this patent UNITED STATES PATENTS 2,708,290 Neu et al May 17, 1955 2,787,025 Balmes Solanas Apr. 2, 1957 2,865,057 Cotchett et al Dec. 23, 1958 2,943,361 Cotchett July 5, 1960 2,943,362 Butler July 5, 1960 2,947,039 Rulon-Miller et al Aug. 2, 1960

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