US2840019A

US2840019A - Backing fabric feed means for tufting machine and method

Info

Publication number: US2840019A
Application number: US531107A
Authority: US
Inventors: Beasley Max Marion
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-09-20
Filing date: 1955-08-29
Publication date: 1958-06-24
Anticipated expiration: 1975-06-24
Also published as: US2857867A

Description

June 24, 1958 M. M. BEASLEY 2,840,019

BACKING FABRIC FEED MEANS FOR TUFTING MACHINE AND METHOD Filed Aug. 29, 1955 2 Sheets-Sheet l INVENTOR I MAX M. BEA-S'LEV ATTORNEY M. M. BEASLEY June 24, 1958 BACKING FABRIC FEED MEANS FOR TUFTING MACHINE AND METHOD Filed Aug. 29, 1955 2 Sheets-Sheet 2 IN VENTOR MAX M BEASLEV ATTORNEY United States Patent BACKING FABRIC FEED MEANS FOR TUFTING MACHINE AND METHOD Max Marion Beasley, Chattanooga, Tenn.

Application August 29, 1955, Serial No. 531,107 9 Claims. (Cl. 112-7 This invention is a drive mechanism for the feed rolls by which backing fabric is fed through a multiple needle tufting machine and is an improvement on similar apparatus shown and described in my co-pending. application, Serial No. 456,995, filed September 20, 1954.

In the past,'considerab1e difiiculty has been occasioned in the operation of multiple needle tufting machines when engaged in producing yardage goods such as carpets, bedspreads,,and the like, by the appearance of stop marks in the finished fabric as a resultof the inertia of the roll of backing fabric from which the machine is supplied, when starting up the machine, and/or by the acceleration and deceleration of machinecparts during stopping and starting periods of the machine after a run has been initiated. These stop marks, extend transversely of the finished fabric and are occasioned by a variation in the length of stitches formed by the machine due to variations in the rate of feed of the backing fabric resulting from the above-recited causes, and com I have described a method and apparatus for accomplishing these purposes by developing a controlled tension in the base fabric as it is passed through the needle mechanism, said tension beingjof sufiicient magnitude to eliminate backlash in separate gear trains employed to drive feed rolls placed fore and' aft of the needle mechanism. The tension is developed by'driving the aftffeed roll at a slightly higher rate of speed than the speed of the fore feed roll while maintaining the fabric and feed rolls in' substantially non-slipping engagement. In this arrangement tension in the base fabric, in effect, loads the fore and aft feed rolls over and above the fabric feeding load thereon, with the result that the gear teeth of the feed roll driving trains are maintained in contact at all times and thus all backlash in these gear trains is eliminated. T o enhance these results, the gear trains each include worm gears which are self-locking against reverse or retrograde movement. i i I While the arrangement proposed in my co-pending application, Serial'No. 456,995, is effective in eliminating stop marks in the finished fabric by precluding all movement of the base fabric except when the main shaft, which drives the feed rolls, is in operation, the arrangement is subject'to the objection that it requires frequent change and adjustment of the relative speed of the fore and aft feed rolls, since the desired degree of tension in the base fabric is dependent upon such variable factors as the texture of the base fabric and/or its width. Thus, when the tension in the base fabric alone is rehed upon "ice to eliminate backlash in the driving gears, speed adjustments may become troublesome when changes in the types and width of the base fabric are frequent. Furthermore, such adjustments at times requiredelicate manipulation of the speed controls to maintain proper tension in the cloth to meet operational demands.

In my co-pending application, the total tension force developed in the base fabric may be considered as comprising two components, i. e., the tension force necessary to insure a smooth even feed of the base fabric, and a greater tension force necessary to eliminate backlash in the driving gears. With these facts in mind, the present invention proposes to develop within the base fabric by means such as described in my co-pending application, Serial No. 456,995, only that amount of tension that is necessary to insure a smooth evenfeed of the fabric when the needles are in operation, and to provide other means, operable to eliminate backlash in the gear trains, the latter means operating without regard to the amount of tension prevailing in the base fabric as it passes through the needle mechanism.

One object of the invention is to provide drive means for the feed rolls of the base fabric which includes means for driving feed rolls at the rear of the needle mechanism at a slightly greater rate of speed than feed rolls in front of the needle mechanism are driven, while maintaining a substantially non-slip driving relation between the feed rolls and the fabric to thereby develop tension in the fabric as it is passed through the needle mechanism, and while loading the feed rolls independently of the fabric feed load to eliminate backlash in the gear trains which drive the rolls. 7

Another object of the invention is to drive the fore and aft feed rolls through separate gear trains operatively connected respectively to the feed rolls and arranged to drive the aft feed roll at a predetermined speed slightly exceeding the speed of the'fore feed roll and wherein said feed rolls are otherwise drivingly interconnected by means tending to drive the aft feed rolls from the fore feed rolls at a speed greater than said predetermined speed.

- Another object of the invention is to provide fore and aft feed rolls separately driven by gear trains which maintain the aft feed roll at a predetermined speed which is greater than the speed of the fore feed roll while concurrently loading the rolls over and above the normal feed load thereon by drivingly connecting the rolls so that the fore feed roll tends to drive the aft feed roll at a speed greater than the predetermined speed while compensating by a slip clutch the speed differential between the two driving means for the aft feed roll.

Another object of the invention is to provide a transmission mechanism for the feed rolls which will eliminate entirely or reduce to a negligible minimumthe backlash in the' transmission mechanism and thereby preclude stop marks in fabric due to irregular movement of the base fabric with respect to the needle mechanism, i. e., over run and/or reverse movement, as a result of stopping and again starting the machine after a yardage run has been initiated. 7 These and other objects of the invention will become apparent from a consideration of the following specification read in connection with the accompanying drawings wherein a preferredmodification of the invention is shown and wherein Fig; l is a vertical sectional view of a multiple needle tufting machine embodying the present invention,

Fig. 2 is an end elevation of a tufting machine equippe with the present invention, a

Fig. 3 is a vertical sectional view through the transmission housing, I r

Fig. 4 is a transverse sectional view through the housing taken on the line 4-4 of Fig. 3, and

Fig. 5 is a transverse sectional view taken on the line 55 of Fig. 3, I

Fig. 6 is a perspective view of the opposite end of the machine shown in Fig. 2 and showing the loading means,

character 3, the needle mechanism being driven by an overhead shaft 4 which may be driven by any conventional means (not shown). Thread or yarn 5 is fed to the needle mechanism from a source (not shown) by yarn feed rolls 6. The base fabric 7, which is provided with pile tufts or loops by the needle mechanism in a well-known manner, may be drawn from the supply roll (not shown) over stationary roll 8 by the front fabric feed roll 9. At the rear of the machine there are provided the fabric feed roll and stripper roll 11. The feed roll 10 draws the base fabric 7 through the needle mechanism of the machine and the needles project the pile tufts or loops through the fabric in a well-known manner. The fore and aft feed rolls 9 and 10 are positively driven by drive mechanism housed within the transmission casing 12 secured to the machine frame. 1 by any suitable means. The drive mechanism within the casing 12 is driven from the overhead shaft 4 by means clearly shown is Fig. 2.

The drive means for the transmission mechanism housed within the casing 12 comprises a V pulley 13 secured to shaft 4 and driving a V belt 14 which operatively drives one pulley of a multiple V pulley change .speed device indicated generally by the reference character 15. The change speed pulley device 15 is of conventional form and includes an intermediate axially movable sheave which in response to belt tension in the belts on opposite sides thereof will shift axially on the pulley spindle to increase the effective diameter of one belt pulley and simultaneously and correspondingly decrease the effective diameter of the other belt pulley in a wellknown manner. The tension on the belt 14 may be varied by rocking the pulley device. 15 about the mounting spindle 16 by manipulation of the threaded rod 17 which has one end rotatably connected to an arm 18 which in turn is operatively connected to the pulley device 15. The threaded portion of the rod 17 passes through a threaded sleeve or nut supported for rocking movement between arms 17a as shown in Fig. 2. Thus, as the threaded rod 17 is rotated, the pulley device 15 may be rocked clockwise or counterclockwise about the pivot 16 to increase or decrease respectively the diameter of the pulley to which the V belt 14 is connected and simultaneously to correspondingly decrease or increase the effective diameter of the pulley to which the V belt 19 is connected. The V belt 19 drives a multiple ex- Ipansible V pulley 20 mounted on a shaft 21 and the pulley 20 drives through a V belt 22 an expansible V pulley 23 mounted on shaft 24. The V pulleys 20 and 23, as shown inFig. 2, are of the expansible type and in response to adjustment of the nuts, 21a and 24a, the space between, the pulley sheaves may be made greater or less and thus vary the effective diameter of the respective pulleys. A belt guide and tension device 25 for the belt 22 is shown, carrying an idle pulley 26 and the latter is adjustable on the gear casing 12 by means of a slot 27 and bolt members 28 to maintain suitable tension The shafts 21 and 24 are mounted in suitable bearings in the walls of the gear casing 12, and project therefrom on the belt 22 in all positions of adjustment of the pulleys 20 and 23..

at one end to receive the V pulleys 20 and 23 respectively, as clearly shown in Fig. 2 of the drawing. Within the gear casing 12 the shaft 21 carries a helical gear 29 which is operatively engaged with a mating gear 30 mounted upon a shaft 31 journaled in suitable bearings 32 and carrying a worm 33. The worm 33 is operatively engaged with a worm gear 34 which is splined to a shaft 35 which extends across the rear of the machine, generally parallel to the bank of needles 3 and is suitably journaled in bearings 35a, carried by the machine frame 1. The shaft 35 carries the rear feed roll 10 and one end thereof projects into the gear casing 12 through guide bearings 36 and 37 and is driven by the gear 34 as shown.

Shaft 24 is similarly supported for rotation by bearings in the walls of the gear casing 12 and has splined thereto within the casing a helical gear 38 which meshes with a gear 39 splined to a shaft 40 journaled in suitable bearings 41 and carrying a worm 42. The worm 42 meshes with a worm wheel 43 splined to shaft 44 which extends across the front of the machine generally parallel to the bank of needles 3 and is mounted for rotation in suitable brackets 44a carried by frame 1. The shaft 44 carries the fore feed roll 9, and one end of this shaft projects into the housing 12 and is driven by gear 43 as shown.

The details of the gear casing 12 are unimportant, but the casing may be provided with suitable

removable closure plates

45, 46, 47, and 48 to provide access to the gear elements of the transmission. Suitable lubrication may be provided within the casing 12 by any convenient means including ducts 49 for delivery of lubricant to the bearing elements of the transmission mechanism.

As shown in Fig. 1, the rolls 9 and 10 are provided with fabric-penetrating spikes S to insure non-slipping feed of the fabric.

In operation, the main shaft 4 of the machine is driven by any suitable source of power such as an electric motor (not shown), by V belt 50. As previously described, the transmission mechanism for driving the feed rolls 9 and 10, is driven from the main shaft 4 of the machine so that the feed rollers are driven in timed relation to the needle mechanism. The length of the stitches looped into the base fabric is of course dependent upon the rate of feed of the base fabric, and this in turn may be controlled by adjusting the speed pulley device 15 as desired. Thus, if the effective diameter of the pulley to which V belt 14 is engaged is increased, the speed of the feed roll transmission mechanism is increased, and vice versa. Generally speaking, a speed change of about 2 /2 to one may be effected by the pulley drive 15 as shown, and this will yield a range of stitch lengths of approximately from 4 to 10 stitches per inch. If greater range of variation is desired, a change in the size of sheaves in the pulley drive '15 may be readily made. Any change in speed of the feed roll transmission mechanism due to adjustment of the pulley drive 15 has no effect upon the relative speed difference in the shafts 21 and 24 since the percentage of speed difference in the latter shafts is determined by the adjustment of the expansible V pulleys 20 and 23. Thus, for any given adjustment of the pulley speed change device 15, the expansible pulleys 20 and 23 may be relatively adjusted to give any desired percentage of speed difference between these shafts to thereby drive feed rolls 9 and 10 at relative speeds such as to create a desired tension in the base fabric 7 as it passes through the needle mechanism.

It should be noted that while I have described a change speed drive means between shafts 21 and 24, this while desirable, is not necessary where separate means are provided to eliminate backlash by loading the feed roll shafts over and above the fabric feed load thereon as fully described hereinafter. Thus, for the change speed belt and pulley drive 20-22-23 provided between shafts 21 and 24, 1 may use a fixed ratio drive of any desired form such as a chain and sprocket drive (not shown) designed to drive the aft roll (or shaft) at a slightly higher speed than the fore roll (or shaft). Experience has shown that when the tension in the fabric is relied on only to provide a smooth even feed through the needle mechanism a speed differential between the fore and aft feedrolls of approximately 2 percent is usually suflicient; t .7 I

It will be noted that each feed roll 9 and 10 is driven by a separate train of gearing; the roll 9 by the gear train 383942 43, and the roll 10 by the gear train 2930'33p34. In each instancethe last two gears in the respective train are high reduction worm gears which areself-locking in response to any tendency of the respective rolls 9 and 10 to move in reverse. This reduces backlash to a'minimum. The ratio of reduction between the gears 42-43 and 3334 is not critical, but it should be high and preferably of the order of 80:1 or greater.

Although any tension in the fabric between the rolls 9 and 10 will tend to reduce backlash in the gear trains which drive the feed rolls, it is not always desirable to develop sutficient tension in the fabric to eliminate completely this lost motion in the gears as proposed in my co-pending application, Serial No. 456,995. I, therefore, propose to provide separate means for controlling backlash in the gears and in Fig. 6 I have shown such means operatively associated with the feed rolls 9 and 10. Thus the fore feed roll shaft 44 and the aft feed roll shaft 35 may be extended beyond the end of the machine opposite that shown in Fig. 2. The extension of shaft 35 may be supported in any suitable bracket B and may have a gear 51 secured thereto. The gear 51 is meshed with a gear 52 carried by a jack shaft 53, the latter being supported in any convenient manner by bracket members B and B The jack shaft 53 extends beyond the end of the machine and is then provided with a slip clutch indicated generally by the reference character 54. The slip clutch may be of conventional design such as shown in Fig.7 and in practice a 6 inch Hilliard No. 311 clutch has proved quite satisfactory.

The slip clutch 54 may include a friction element 58 secured to the shaft 53 by a key 59 and cooperating with the friction element 58 is a second friction element 60', the latter being connected by spring arms 61 to a hub 62 rotatably mounted on shaft 53. On the hub 62 is secured a sprocket 55 as by a key 63. A nut 64 threaded on the end of the shaft 53 bears against a thrust collar 65 to urge the friction element 60 resiliently into engagement with the friction element 58to thereby regulate or adjust the degree of slip between the

elements

58 and 60. The sprocket 55 is connected by a sprocket chain 56 to a sprocket gear 57 secured to the extended end of shaft 44 which carries the fore feed roll 9. The extension of shaft 44 may be suitably supported in a bracket B The sprockets 55 and 57 are designed to provide a speed difierential between shafts 44 and 53 of approximately to 7 percent with the shaft 44 tending to rotate the shaft 53 at the higher speed. Obviously, due to the separate gear trains which drive the rolls 9 and at the opposite ends thereof, namely 3839 4243 and 293033-34 respectively, the sprockets 55 and 57 and the sprocket chain 56' are not effective to relatively alter the speed of the rolls 9 and 10 as determined by said separate gear trains, so that the slip clutch 54 is provided to compensate the speed differences between the drive members connected to opposite ends of the feed roll shaft 35. This clutch functions, in effect, to load the roll shafts to an extent sufficient to eliminate substantially all backlash in said gear trains while a desired light tension of the fabric is maintained between the rolls as the fabric passes through the needle mechanism. The degree to which the roll shafts are loaded may be controlled and determined by adjusting the degree of slip of the clutch 54 by the nut 64 in a known manner.

. drive'as by the belt and pulley means 13--14, 19

and 20, anyidesired form of intermittent drive 'means, such as a Ferguson rollerjgeardrive, may be employed between the drive shaft 4 and the shaft 21 without sacrific ing any of the effectiveness of my invention in preventing stop 'marksf in the resulting fabric. It iswell known in the to; drive the base fabric intermittently in timed relation ,to needle movement,'and it to be understood that where thet'erms drive means or .drive mechanism are used herein and in the appended claims,

said terms comprehend either a continuous drive means or an intermittent drive means.

Having thus described my invention it is apparent that by providing loading means for the roll shafts separate from the means for developing tension in the base fabric, I am able to eliminate backlash in the gear trains which drive the rolls while maintaining only that degree of tension in the base fabric as is necessary to insure a smooth even feed thereof through the needle mechanism of the machine. This precludes any difiiculty such as deflection of the needles due to excessive tension in the fabric while insuring a smooth even feed of the fabric and a uniform operation of the machine which together produces a finished fabric entirely free of stop marks.

It will be understood that while I have shown a preferred embodiment of my invention, those skilled in the art will appreciate that various changes may be made in size and proportion of the parts without departing from the spirit of the invention which is set forth more particularly in the appended claims.

I claim:

1. In a multiple needle tufting machine including needle mechanism and fabric feed rolls positioned fore and aft with respect thereto, separate drive means for the feed rolls operating to drive the aft feed roll at a speed that is greater than the speed of the fore feed roll and means drivingly interconnecting the feed rolls and tending to drive the aft feed roll at a speed greater than said first mentioned speed thereof.

2. The apparatus described in claim '1 wherein the means drivingly connecting the feed rolls includes means for compensating the speed differential between said first mentioned speed of the aft roll and the speed at which said interconnecting means tends to drive it.

3. The apparatus described in claim 2 wherein said speed compensating means includes a slip clutch.

4. The apparatus described in claim 2 where means are operatively associated with said separate drive means for the feed rolls for relatively varying the speed of the fore and aft rolls and wherein said speed compensating means includes means for variably loading the fore and aft feed rolls over and above the fabric feed load thereon.

5. In a tufting machine, feed rolls mounted fore and aft of the needle mechanism thereof, separate gear trains connected to the respective feed rolls for driving the rolls at different speeds, the aft feed roll being driven at a greater speed than the fore feed roll to develop tension in the fabric fed by said rolls, and means for loading the feed rolls over and above the fabric feed load thereon to thereby eliminate backlash in the gear trains driving the said rolls.

6. The apparatus described in claim 5 wherein the loading means comprises means drivingly interconnecting the feed rolls and tending to drive the aft feed roll at a speed greater than that imparted to said feed'roll by the gear train connected thereto, and speed compensating means operatively interposed between the aft feed roll of the needle mechanism, a first drive means comprising separate gear trains operativ ely eonnected to the respective ie e d rolls at one end thereof and arranged to drive the aft feed roll at a speed greater than the speedof the omft qd m t n *1 se n d i e means p n means drivingly interconnectingthe opposite ends of the .feed rolls and tending I9 drive 1the' aft feed roll at a speed {greater than the speed imparted thereto by said first ,drive means, and speed compensating means .opera tiyely interposed between the aft feed roll and said second mentioned drive rneans therefor.

9.T he apparatns descr ibed in claim 8 wherein said 8 speed compensating means icomprises a slip el ntch including means for adjusting the .pereenta ge of Slip thereof. References Cited in thefile ofthis' patent UNITED STATES PATENTS 1,060,799 Van Horn May 6, 1913 1 ,715,119 Clarkson May 28; 1929 2,090,022 Baynton et a1. Aug. 17, 1937 2,556,068 Crawford June 5, 1951 2,679,218 Jones May 25, 1954 2,682,238 Reeves June 29,