US3486320A

US3486320A - Method and apparatus for false twisting of yarn

Info

Publication number: US3486320A
Application number: US482430A
Authority: US
Inventors: Denis Albert Edward Mattingly; Reginald S Gilchrist
Original assignee: Klinger Manufacturing Co Ltd
Current assignee: Klinger Manufacturing Co Ltd
Priority date: 1964-08-29
Filing date: 1965-08-25
Publication date: 1969-12-30
Anticipated expiration: 1986-12-30
Also published as: GB1123793A

Description

D 3 1959 D. A. E. MATTINGLY E AL 3,485,320

METHOD AND APPARATUS FOR FALSE TWISTING YARN Filed Aug. 25, 1965 3 Sheets-Sheet 1 Dec. 36, 1969 D. A. E. MATTINGLY ET AL 3,486,320

METHOD AND APPARATUS FOR FALSE TWISTING YARN Filed Aug. 25, 1965 3 Sheets-Sheet 2 D 30 1 D. A. E. MATTINGLY ET A 3,486,320

METHOD AND APPARATUS FOR FALSE TWISTING YARN Filed Aug. 25, 1965 3 Sheets-Sheet 5 z 27 i? "J? 7/ a 75 5-1 M I WWW) US. Cl. 5735 14 Claims ABSTRACT OF THE DISCLOSURE The invention is directed to a method and apparatus for false twist crimping a plurality of yarns, by passing said yarns through first feed means, across a heated surface extending in the horizontal direction along the apparatus, through twisting heads and second feed means that are horizontally disposed relative to their associated first feed means in the direction of the length of the apparatus and by passing the yarns to winding mechanisms, which may be of a changeover type, arranged in parallel rows spaced apart in the vertical direction. The yarn tensions preferably are maintained within certain ranges between the various means and while passing across the heated surface.

This application is a continuation-in-part of application Ser. No. 327,203 filed Dec. 2, 1963, now US. Patent No. 3,336,738, and Ser. No. 363,574, filed Apr. 29, 1964, now US. Patent No. 3,345,003.

This invention relates to false twisting of yarn and particularly to apparatus and a method of false twisting a plurality of yarns.

The expression yarn is used herein to include monofilament, multi-filament and stable fibres formed wholly or partially of a plastics material or materials so that the yarn is capable of being heat set. Examples of such plastics materials are polyamides and polyesters.

According to one aspect of the present invention there is provided apparatus for false twist crimping a plurality of yarns comprising first feed means, a heated surface extending in the horizontal direction along the apparatus, said first feed means being disposed above the level of the heated surface, twisting heads disposed below the level of the heating surface and horizontally disposed relative to their associated first feed means in the direction of the length of the apparatus, second feed means disposed below the twisting heads, package winding mechanisms for forming the yarn into packages disposed below the twisting heads, each winding mechanism having two spindles disposed side by side in parallel relationship, reciprocable yarn guide means adapted to form the yarn evenly into packages on either of the spindles, and changeover means to cause the yarn to be formed into a package on one of the said two spindles and subsequently to be formed into a package on the other of said two spindles.

The package winding mechanisms can be arranged in parallel rows spaced apart in the vertical direction. The

nited States Patent 3,486,320 Patented Dec. 30, 1969 ICC apparatus can include actuating means adapted to automatically actuate the changeover means associated with each of the package winding mechanisms when the packages being formed on one of said two spindles reaches a predetermined size. The actuating means can includes a plurality of pneumatic cylinders, each pneumatic cylinder being operatively connected to a changeover means and operated by a single source of compressed air.

According to another aspect of of the present invention there is provided apparatus for false twisting a number of yarns comprising means for supporting a plurality of supply bobbins, a heater having a heated surface extending in the lengthwise direction of the apparatus and in contact with which the yarns are caused to pass, twisting devices disposed on the opposite sides of the heater to the supply packages, feed means for feeding the yarn from the supply bobbins to the heater and to the twisting devices, twist stop means for preventing the twist imparted to the yarns from reaching the supply bobbins, and package forming mechanism disposed below the twisting devices and arranged in four rows vertically spaced apart.

The apparatus can have the means for supporting the plurality of supply bobbins, the twisting devices, the feed means, the twist stop means and the package forming mechanism disposed along both sides of the apparatus for false twisting yarn on both sides thereof, the heater extending around the machine in a horizontal plane to provide a heated surface for yarns on both sides of the apparatus.

At least a part of the yarn path in contact with the heated surface can be at an acute angle in the range of 2 to 10 to the horizontal direction of the surface, and preferably in the range 3 to 4.

According to a further aspect of the present invention there is provided apparatus for false twisting a plurality of yarns including first positive feed means, second positive feed means, a plurality of associated yarn guide means on both sides of the apparatus, a twisting zone including twisting devices and yarn heating means, said first and second positive feed means being adapted so that in use the tension of the yarn therebetween is regulatably positively controlled, said heating means comprising a hollow body disposed on each side of the apparatus, said hollow bodies being interconnected at their ends and having at least one heated surface disposed lengthwise along the apparatus in contact with which yarns are caused to travel prior to passing to the false twist devices, and yarn oiling means comprising a reservoir, 2. first driven roller, a part of the periphery of which extends into the reservoir, and a second roller in driving engagement with said first roller, the yarn passing in contact with the periphery of the second roller. The first driven roller can be driven by a variable speed electric motor.

According to yet another aspect of the present invention there is provided a method of false twisting yarn including the steps of passing the yarn through a heating zone, false twisting the yarn about its lengthwise axis so that the twist imparted to the yarn runs back to within the heating zone and positively feeding the yarn to a take-up spool, wherein the tension in the yarn after the false twisting step and before said positive feed step is between two and three times the tension in the yarn as it enters the false twisting step, and the tension in the yarn being fed to the take-up spool being between /2 gram and 4 grams. The tension in the yarn can increase by between /3 and /3 as it passes through the heating zone.

By way of example, an embodiment of the present invention will now be described with reference to the accompanying diagrammatic drawings in which:

h FIGURE 1 is a side elevation of a false twisting mac me;

FIGURE 2 is an end elevation of the false twisting machine along the line II-II in FIGURE 1;

FIGURE 3 is an end elevation on an enlarged scale of the oiling means of the apparatus shown in FIG- URES l and 2; and

FIGURE 4 is a side elevation of the oiling means.

As shown in FIGURE 1, one form of false twisting apparatus according to the present invention includes a plurality of means 1 for supporting supply bobbins of yarn 2 on top of a frame (not shown). Below each supply bobbin 2 is a yarn steadying or stabilising device 3 which may conveniently comprise a length of wire bent in a zig-zag manner to form a comb-like or gate device, the yarn in use being threaded so as to pass on opposite sides of certain of the wires. Such a device serves to steady the yarn from the path it assumes as it is unwound from the supply bobbin without exercising more than a minimum amount of drag upon the yarn.

Below the stabilising device 3 is an adjustable yarn tensioner 4 which may conveniently comprise an adjustable gate device having alternate fingers mounted to be capable of relative movement, or a magnetic hysteresis tensioner in which a magnetic field acts as a brake to the movement of the wheel around which the yarn passes, the wheel gripping the yarn and retarding its passage.

First positive feed means 5 comprises a driven shaft 6 extending lengthwise along the apparatus and idler rollers 7, equal in number to the number of supply bobbin support means, the idler rollers 7 being rotatable about axes parallel to the axis of rotation of the driven shaft 6. The idler rollers are releasably urged into contact with the driven shaft by detent mechanisms 8 to form a nip between the idler rollers and the driven shaft. A second positive feed means 9 again comprising a driven shaft 10 and a plurality of idler rollers 11 is similar to, and located below the first feed means 5, a twisting zone including heating means 12 and twisting means 13 being defined therebetween. The peripheries of the

idler rollers

7 and 11 are provided with a surface of polyurethane 14 to enhance the grip of the nip of the rollers upon the yarn.

The heating means 12 comprises two horizontal enclosed

members

15 and 16 extending lengthwise along both sides of the machine and interconnected at their ends by enclosed members one of which is shown at 17. Means (not shown) are provided for circulating a fluid, preferably a non-carbonising oil of low vapour pressure, around the closed circuit formed by the hollow members and for heating the fluid to a controlled temperature. The

members

15 and 16 are provided with convexly

curved faces

18 and 19 which face upwardly and outwardly. The other sides of the

members

15 and 16 and all sides of the interconnecting members are preferably surrounded by "a heat insulating material. Yarn guides are provided adjacent and/or on the curved surface of the heating means to guide the yarns thereover. As shown in FIGURE 1 the yarn paths across the heater faces 18 and 19 are at a small angle to the horizontal direction of the faces, the width of the faces in the vertical direction being small relative to the length of the faces.

The false twist means 13 are located below the heater and may comprise any device capable of twisting the travelling yarn such as means for rotating a false twist spindle or means which frictionally engage the yarn and cause it to rotate, for example, a moving belt.

Below the second positive feed means 9 are oiling means 20 as shown more clearly in FIGURES 3 and 4.

A first roller 21, mounted on a driven shaft 22 is arranged so that part of its periphery extends within a reservoir 23 containing oil 24 as required. A second roller 25 is mounted on a shaft 26 which in turn runs in

slots

27 and 28 in

support brackets

29 and 30 secured to the frame of the apparatus (not shown). The driven shaft 22 is rotated by means of a variable speed electric motor 31 (see FIGURE 1) and the roller 21 is rotated, the periphery 32 of which carries with it oil which is then transferred to the periphery of the roller 25. Roller 25 rotates, the weight of the roller 25 serving to maintain it in driving engagement with the roller 21; yarn 33 passing through the machine passes in contact with the roller 22 whereby oil is picked up by the travelling yarn.

With this arrangement the quantity of oil on the periphery of the roller 25 is metered by reason of its contact with the roller 21 so that a constant quantity of oil is on the surface which the yarn contacts thus ensuing a constant pick-up of oil by the yarn.

A plurality of rollers 21 are mounted on a common drive shaft 22 On each side of the apparatus and extend into common reservoirs 23 extending lengthwise along both sides of the apparatus. The oil may be replenished manually or automatically in conjunction with a controlled feed, or a level sensing unit, from a suitable source of supply. The reservoirs may be interconnected to be fed with oil from a single source of supply.

At the lower part of the apparatus is arranged winding mechanism for forming the yarn into self-supporting packages. Each winding mechanism comprises a pair of

spindles

34, 34a on which bobbins can be releasably secured. Opposite each spindle is a reciprocable yarn guide 35, 35a secured to an inextensible metal tape 36. the ends of which are wrapped around and secured to pulleys (not shown) which are oscillated by a suitable transmission means to impart the reciprocating motion to the yarn guides 35 and 35a. The yarn guides 35 and 35a are formed with tapered outer shoulders so as to be self-catching with respect to the yarn.

Each of the

spindles

34, 34a are provided with castellations at their adjacent ends and the spindles are releasably supported in carriers (not shown) arranged to raise and lower the spindles as hereinafter described.

A driven shaft 37 extending along the machine forms a driving roller for the

spindles

34, 34a, the spindles or packages being formed thereon being driven at a constant peripheral speed.

Associated with each pair of

spindles

34, 34a is changeover means comprising an oscillatable arm 38 which extends between each pair of spindles and has a yarn guide 39 at one end thereof. A further yarn guide 40 is mounted on an extension 41 of the arm, the extension 41 extending normal to the axis of the arm 38 so that, as shown in FIGURE 1, the yarn guide 40 is approximately opposite the mid-point of the travel of the reciprocating guide 35. Means 42 is adapted to cause the arm 38 to oscillate from the position shown in FIGURE 1 to a second position such that the yarn guide 40 is approximately opposite the mid-point of the travel of the reciprocating guide 35a.

The winding mechanisms are arranged in four tiers spaced vertically above each other as shown.

The first and second positive feed means 5 and 9 and the driven shafts 37 for rotating the take-up spools are driven by a single electric motor 43 through transmission means 44 which includes a form of variable gearing whereby the relative speeds of the driven shafts 6 and 10 of each of the feed means and the shafts 37 for rotating the take-up spools may be varied. Conveniently the transmission can include a chain drive to each of the driven shafts which are provided with interchangeable sprockets to vary their relative speeds.

In operation the first feed means 5 draws the yarn 33 from the supply bobbin 2 through the guide means 3 and the tensioning means 4, the yarn passing through the nip of the driven shaft 6 and the idler roller 7 of the first feed means 5 and being fed into the twisting zone. The yarn passes at an angle over the curved faces of the heater 12 and is twisted by the false twist means 13, the twist running back in the yarn over the heater and being prevented from running back further by the first feed means 5 which forms a twist stop. The second feed means 9 forms a second twist stop, the two feed means together defining the limits of the twisting zone. The combination of heating and twisting the yarn results in a crimped yarn which is then fed through the oiling means 20. As the yarn passes through the oiling means it is contacted by the oiling roller and oil carried round on the surface of the roller is picked up by the travelling yarn, the amount of oil so transferred to the yarn being a function of the speed of the roller. By adjusting the speed of the drive means 31 the oil pick-up of the yarn may be varied up to a maximum oil take-up of 7% by weight.

From the oiling means the yarn passes through the guide 39, the guide 40 and the reciprocating guide on to a bobbin secured to the spindle 34 to form a package of yarn. When the package reaches a predetermined size the spindle 34a carrying an empty bobbin is lowered by its carrier into driving engagement with the driving roller formed by the shaft 37. The means 42 operates to oscillate the arm 38 to a second position such that the guide is opposite the empty bobbin. This oscillating movement lifts the yarn from the reciprocating guide 35 and draws it across the gap between the

spindles

34 and 34a. The yarn is gripped by the castellations on the spindle 34a and becomes anchored thereto. The yarn breaks between the two spindles by reason of the difference in their rates of rotation due to the difference in the outer diameters of the full and empty bobbin. The yarn is then lowered as the arm 38 reaches the limit of its travel so that the yarn is laid in the path of the reciprocating guide 35a which engages the yarn and commences to traverse it backwards and forwards to form a package on the spindle 34a.

The full bobbin is then lifted out of driving engagement with the shaft 37 by its supporting carrier. The package can then be removed and an empty bobbin placed on the spindle so that when the package being formed on spindle 34a is completed, the yarn can be fed to the empty spool by operating the arm 38.

Whilst the operation of the mechanism has been described with respect to a single mechanism, each of the means 42 which oscillate the arms 38 may be arranged to be actuated simultaneously. Conveniently the means 42 can comprise a movable rack engaging a pinion secured to the arm 38, each of the racks being operated by a pneumatic cylinder, each cylinder being operated from a single compressed air source. Thus all of the winding mechanisms can be arranged to commence and finish forming packages at the same time so that packages of a uniform size are formed throughout a machine.

As described, the yarn is positively fed into the twisting zone by the first drive rollers 5, the relative speeds of the first and second drive rollers being adjusted to allow for a desired amount of shrinkage during the heating step and to obtain the desired final tension in the yarn as it enters the false twist means 13. The tension in the yarn increases as it passes across the heater by reason of its contact therewith, the increase being between /3 and /3 of the tension in the yarn before it passes across the heater. As the yarn passes through the false twist head it is desirable to increase the tension in the yarn so that the tension in the yarn between the head and the second positive feed means is between two and three times the tension in the yarn as it enters the head. In this way the yarn can be gripped and efiiciently twisted by the false twist head.

Similarly, the speed of the take-up spools 33 relative to the speed of the second drive rollers is arranged so that yarn is wound on to the take-up spools under a tension of between /2 and 4 grams. In this way a firm and stable package is formed without it being wound so tightly that, as the package grows in size, the inner layers are deformed and the ends of the package bulge outwards.

The tension in the yarn between the first positive feed rollers and the heater may be between 4 and 12 grams; the tension in the yarn between the heater and the false twist head may be between 5 and 20 grams; the tension in the yarn as it leaves the false twist means and prior to the second positive drive rollers may be between 12 and grams; the tension in the yarn being fed to the take-up spool may be between /2 and 4 grams. A preferred range of tension is 5 to 10 grams, 8 to 16 grams, 20 to 50 grams and 1 to 3 grams respectively, for example 6 grams, 9 grams, 25 grams and 1 gram, respectively.

By processing yarn in this way we have found that crimped yarn can be produced at high throughput speeds having improved crimp rigidity characteristics together with improved strength, an even afiinity for dyestuffs, and improved stitch clarity in fabric formed from the yarn, all of which lead to improvements in articles made from the yarn. In order to maintain the desired tensions at the various stages of the process it is necessary to take into account variations in the spin finish applied to different yarns. For this reason we have found that, when using a false twist head having a hollow spindle with a cross-pin extending across the bore, it may be necessary with certain yarn to wrap the yarn more than once around the cross-pin in order to maintain the desired increase in tension at the false twist head.

Alternatively, the yarn may be positively tensioned within the twisting zone by means of the adjustable tensioning means 4 alone, which may be desirable for particular types of yarn. This is achieved by rendering the first drive rollers 6 and 7 inoperative either by leaving the idler rollers 7 out of contact with the driving roller 6 as by means of the detent mechanism 8, by disconnecting the drive to the driving shaft 6 or arranging by means of guides for the path of the yarn to by-pass the driving rollers.

When the first drive rollers are not in use the tensioning device 4 forms a twist stop defining one end of the twisting zone.

Twist stop means may be included between the first and second means at one or both ends of the twisting zone to define the twisting zone therebetween. This may be particularly desirable at the entry end of the zone since the twist running back in the yarn may cause excessive wear of the operative surfaces of the driving rollers 6 and 7 when these are used as a twist stop. Such a twist stop means may comprise for example the adjustable tensioning means 4 as described in British patent specification No. 908,112 with the magnetic means so adjusted such that the device exerts substantially no drag on the yarn passing therethrough.

The apparatus described having a magnetic hysteresis tensioner 4 and a false twist head incorporating a hollow twist spindle with a cr0sspin was used to process yarn according to the following examples.

EXAMPLE 1 denier, 34 filament nylon 66 was processed at 416 feet per minute throughput speedfThe tension in the yarn between the first positive feed rollers and the heater was 8 grams, the tension between the heater and the false twist head was 11 grams and the tension after passing through the false twist head and before reaching the second positive feed rollers was 30 grams. The yarn was fed to the take-up package under 2 grams tension. The false twist spindle rotated at 400.000 rpm, the yarn receiving a twist of turns per inch. The heater was at a temperature of 230 C. The yarn passed once around the cross-pin in the twist spindle.

7 Yarn so produced was found to have a crimp rigidity (by H.A.T.R.A. test) of 41% and a tensile strength of 4.2 grams/ denier. Fabric knitted from the yarn exhibited a pleasing feel and hand and when dyed showed no bars or streaks.

EXAMPLE 2 30 denier, filament nylon 66 was processed as in Example 1, the tensions in the yarn being 6 grams, 7% grams, 24 grams and 1 gram, respectively. The yarn was processed at a throughput speed of 341 feet per minute, the false twist spindle rotating at 450,000 rpm. to twist the yarn at 110 turns per inch, the yarn passing once around the cross-pin. The heater was at a temperature of 220 C.

The yarn produced was found to have a crimp rigidity (by H.A.T.R.A. test) of 60% and a tensile strength of 4 grams/denier. This was a high stretch yarn and fabric knitted from the yarn had soft hand and excellent elasticity.

EXAMPLE 3 205 denier, 34 fiilament nylon 66 was processed as in Example 1, the tensions in the yarn being 12 grams, 16 grams, 48 grams and 2 grams, respectively. The throughput speed was 443 feet per minutes, the twist spindle rotating at 250,000 r.p.m. thus twisting the yarn at 47 turns per inch. The yarn was passed twice around the cross-pin and the heater temperature was 185 C.

This yarn was tested and found to have a crimp rigidity (by I-I.A.T.R.A. test) of 23% and a tensile strength of 4.5 grams/denier. Although having an improved crimp rigidity with regard to the twist inserted in the yarn, this yarn had limited stretch characteristics and was suitable for coarse gauge knitting such as outerwear.

In each example the packages of crimped yarn were firm and stable, deformation at the ends of the package being negligible and the yarn was unwound when using the yarn without snagging occurring.

What is claimed is:

1. Apparatus for false twist crimping a plurality of yarns comprising first feed means, a heated surface extending in the horizontal direction along the apparatus, said first feed means being disposed adjacent one side of the heated surface, twisting heads disposed adjacent the heating surface and horizontally disposed relative to their associated first feed means in the direction of the length of the apparatus, second feed means disposed adjacent the twisting heads, package winding mechanisms for forming the yarn into packages disposed adjacent the twisting heads.

2. Apparatus according to claim 1 in which said package winding mechanisms are arranged in parallel rows spaced apart in the vertical direction.

3. The apparatus in accordance with claim 1 wherein each said winding mechanism has at least two spindles disposed side by side in parallel relationship, reciprocal yarn guide means adapted to form the yarn evenly into packages on either of the spindles, and changeover means to cause the yarn to be formed into a package by one of said two spindles and subsequently to be formed into a package on the other of said two spindles.

4. Apparatus according to claim 3 including actuating means adapted to automatically actuate the changeover means associated with each of the package winding mechanisms when the packages being formed on one of said two spindles reaches a predetermined size.

5. Apparatus according to claim 4 in which the actuating means includes a plurality of pneumatic cylinders, each pneumatic cylinder being operatively connected to a changeover means and operated by a single source of compressed air.

6. Apparatus for false twisting a number of yarns comprising means for supporting a plurality of supply bobbins, a heater having a heated surface extending in the lengthwise direction of the apparatus and in contact with which the yarns are caused to pass at an angle disposed from the vertical direction, twisting devices disposed on the opposite side of the heater to the supply packages, feed means for feeding the yarn from the supply bobbins to the heater and to the twisting devices, twist stop means for preventing twist imparted to the yarns from reaching the supply bobbins, and package forming mechanism disposed below the twisting devices and arranged in rows vertically spaced apart.

7. Apparatus according to claim 6 having the means for supporting the plurality of supply bobbins, the twisting devices, the feed means, the twist stop means and the package forming mechanism disposed along both sides of the apparatus for false twisting yarn on both sides thereof, the heater extending around the machine in a horizontal plane to provide a heated surface for yarns on both sides of the apparatus.

8. Apparatus according to claim 7 in which at least a part of the yarn path in contact with the heated surface is at an acute angle in the range 2 to 10 to the horizontal direction of the surface.

9. Apparatus according to claim 8 in which the acute angle is between 3 and 4.

10. Apparatus for false twisting a plurality of yarns including first positive feed means, second positive feed means, a plurality of associated yarn guide means on both sides of the apparatus, a twisting zone including a twisting device and yarn heating means, said first and second positive feed means being adapted so that in us the tension of the yarn therebetween is regulatably positively controlled, said heating means comprising a hollow body disposed on each side of the apparatus, said hollow bodies being interconnected at their ends and having at least one heated surface disposed lengthwise along the apparatus in contact with which yarns are caused to travel at an angle disposed from the vertical direction prior to passing to the false twist devices, and yarn oiling means comprising a reservoir, a first driven roller, a part of the periphery of which extends into the reservoir, and a second roller in driving engagement with said first roller, the yarn passing in contact with the periphery of the s cond roller.

11. Apparatus according to claim 10 in which said first driven roller is driven by a variable speed electric motor.

12. Apparatus for false twist crimping a plurality of yarns comprising first feed means, a heated surface extending in a horizontal direction along the apparatus, said first feed means being disposed above the level of the heated surface, twisting heads disposed below the level of the heating surface and horizontally displaced relative to the first feed means in the direction of the length of the apparatus, second feed means disposed below the twisting heads, and package winding mechanisms for forming the yarn into packages, said winding mechanisms being disposed below said twisting heads.

13. A method of false twisting yarn comprising feeding the yarn to a heating zone, passing the yarn through the heating zone and therefrom to means for false twisting the yarn, permitting twist imparted to the yarn by the false twisting means to feed back along the yarn into the heating zone, withdrawing the yarn from the false twisting means and taking up the yarn to form a package thereof, the tension of the yarn being maintained during the feeding thereof to the heating zone in the range of from 4 to 12 grams, during the passing thereof from the heating zone to the false twisting means in the range of from 5 to 20 grams, during the withdrawing thereof from the false twisting means in the range of from 12 to 60 grams and during the taking up thereof to form a package in the range of from V2 to 4 grams.

14. A method according to claim 13, in which the yarn tensions are in following ranges during the following respective stages: from 5 to 10 grams during the feeding of the yarn to the heating zone, from 8 to 16 grams during the passing of the yarn from the heating zone to the false 9 twisting means, 20 to 50 grams during the Withdrawing of the yarn from the false twisting means and 1 to 3 grams during the taking up of the yarn to form a package.

References Cited UNITED STATES PATENTS 3,336,738 8/1967 Mattingly et a1. 57-34 3,345,003 10/1967 Mattingly et a1. 2,900,783 8/1959 Carter et a1. 57-34 10 2,958,921 11/1960 Gilchrist et a1. 5734 3,063,124 11/1962 Hilleary et a1. 5734 3,077,724 2/ 1963 Stoddard et a1.

STANLEY N. GILREATH, Primary Examiner WERNER H. SCHROEDER, Assistant Examiner US. Cl. X.R.