US3528136A

US3528136A - Method and apparatus for side grinding flats on a carding machine

Info

Publication number: US3528136A
Application number: US717062A
Authority: US
Inventors: Alfred R Bechtel Jr; Luther W Bridges Jr; Norman F Chandler
Original assignee: Ashworth Bros Inc
Current assignee: Ashworth Bros Inc
Priority date: 1968-03-05
Filing date: 1968-03-05
Publication date: 1970-09-15
Anticipated expiration: 1987-09-15

Description

P 1970 A. R. BECHTEL, JR.. ET AL 3,

METHOD AND APPARATUS FOR-SIDE GRINDING FLATS V ON A CARDING MACHINE Filed March 5. 1968 4 Sheets-Sheet 1 I NVENTORS ALFRED R. BECHTEL, JRv I 26 v LUTHER W. BRlDGES, JR.

NORMAN F. CHANDLER L 1? J A'ITORNEYS I S ept. 15, 1970 A. RBECHTEL, JR... ET AL 3, 8,

METHOD AND'APPARATUS FOR SIDE GRINDING FLATS ON A CARDING MACHINE Filed March 5, 1968 4 Sheets-$heet 2 Sept. 15, 1970 G- JR" ET AL 3,528,136

METHOD AND APPARATUS FOR SIDE GRINDING FLATS ON A CARDING MACHINE Filed March 5, 1968 4 Sheets-Sheet a AL 3,528,136 IDE GRINDING FLATS wmcnms p 1970 A. R. BECHTEL, JR.

METHOD AND APPARATUS FOR 5 ON A CARDING 4 Sheets-Sheet 1 Filed March 5, 1968 United States Patent "ice 3,528,136 METHOD AND APPARATUS FOR SIDE GRINDING FLATS ON A CARDING MACHINE Alfred R. Bechtel, Jr., Portsmouth, R.I., and Luther W. Bridges, Jr., and Norman F. Chandler, Greenvllle, S.C., assignors to Ashworth Bros. Inc., Fall River, Mass, a corporation of Massachusetts Continuation-impart of application Ser. No. 649,206, June 27, 1967. This application Mar. 5, 1968', Ser. No. 717,062

Int. Cl. D01g 15/08 US. Cl. 19-402 15 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for the side grinding of the wire teeth of card flats as the flats are cycled about their drive path on a carding machine.

RELATED APPLICATION This application is a continuation-in-part of applicants co-pending application, Ser. No. 649,206 filed June 27, 1967, now abandoned, entitled Method and Apparatus for Side Grinding Flats on a Carding Machine.

BACKGROUND OF THE INVENTION This invention relates to the side grinding or reneedling of carding flats and more particularly to a new and improved method and apparatus for side grinding of carding flats as the flats are driven in their operative position on a carding machine.

In the field of fiber alignment by a carding operation, the nep count of the produced yarn bears a direct relation to the condition of the wire teeth on the carding flats. It is desirable to maintain the dimension of the top of the wire teeth, in a direction transverse to the movement of the flats, in the range between .003 inch and .004 inch to thereby provide suflicient space between adjacent rows of wire teeth such that the fiber may be properly aligned. In addition, the abrasive action of emery or the like improves the fiber gripping ability of teeth by providing the sides of the teeth near the point with microscopic corrugations and jagged points or spikes. Abrasion by the fiber during the carding operation tends to polish the sides of the teeth and dull the points thereby decreasing the spacing between the points of adjacent rows and removing the microscopic corrugations and points. This polishing action thereby reduces the ability of the teeth to grip and align the fibers.

Maintenance of the Wire teeth of the carding flats in the proper condition has produced considerable difliculty in the art. In prior art side grinding operations, it is necessary to remove the flats from the carding equipment and place the flats in machines specifically designed for side grinding of the teeth. This prior art side grinding operation is expensive, in terms of man hours expended, down time for the carding machinery and in capital outlay for the purchase of such special grinding machines. As a result of these maintenance expenses, a mill will often prolong the use of a set of flats without reneedling, thereby seriously affecting the quality of the yarn produced.

SUMMARY OF THE INVENTION This invention is employed on a carding machine of the type employing a set of carding flats having on their outer surfaces card clothing comprised of a plurality of gen erally parallel, spaced rows of wire teeth, said flats being driven in cooperative relation with a carding cylinder in a direction parallel to the rows. The width of the flats and the lengths of the rows of teeth are such as to leave open 3,528,136 Patented Sept. 15, 1970 spaces between the ends of the rows of teeth on adjoining flats. This invention includes a method and apparatus for side grinding or reneedling of the teeth on said flats as the flats are driven in their operative position on the carding machine. The flats may be driven in the conventional manner during the operation of the carding machine, or by a second driving means employed for driving the set of carding flats at an increased speed when the remainder of the. carding machine is not in operation.

This invention includes a side grinding assembly mounted in cooperative relation to the card flats. The side grinding assembly includes a grinding head having a plurality of grinding discs each defining abrasive surfaces with a portion of each of said discs being disposed between the rows of teeth on the carding flats. The discs are rotatably driven through a plane defined by the tops of said teeth causing said abrasive surfaces to etfect a side grinding operation on the teeth. The grinding head is operatively mounted on means for reciprocally moving said grinding head across the set of flats transversely of said rows of teeth. This traversing movement is at a speed sufficiently slow relative to the speed of movement of the flats themselves, such that the abrasive surface of each of the discs bears against the moving teeth in a particular row on a particaular flat and substantially never passes across that row on that particular flat but passes from one row to another only in the open spaces between the teeth on adjoining flats. In this manner, the discs are driven back and forth across the set of flats providing a side grinding operation on each side of each row of teeth on the flats without damaging the teeth by passing across the tops thereof. This side grinding may be conducted while the flats are mounted on the card either during the carding operation or when the machine has been stopped and the flats are driven separately.

It is an object of this invention to alleviate the aforementioned difiiculties in the prior art by providing a new and improved method and apparatus for efliciently and effectively accomplishing the side grinding of the card clothing on carding flats as the flats are mounted in their operative position on the carding machine. This invention thereby effectively reduces the expenses attendant the maintenance of carding flats, including either an elimination or reduction of the down time for the carding machinery.

It is a further object of this invention to provide such a method and apparatus whereby the side grinding of the teeth on the carding flats may be accomplished during the carding operation with the carding flats being driven in cooperative relation with the carding cylinder.

It is a further object of this invention to provide such a method and apparatus whereby the driving means for the carding machinery may be disconnected from the carding flats and a second driving means coupled thereto for driving the flats while still mounted on the card at an increased rate of speed when the carding machine is not in operation to thereby expedite the side grinding of the teeth of the carding flats.

It is also an object of this invention to provide such a method and apparatus whereby the teeth on the carding flats can be frequently ground to maintain said teeth at the proper dimension and in the proper condition to appreciably reduce the nep count providing a higher quality yarn at a reduced production cost.

It is a further object of this invention to provide such a method and apparatus employing a grinding head movable transversely of the direction of movement of the carding flats at a speed related to the speed of movement of the carding flats whereby the teeth of the carding flats may be side ground to the proper degree without damaging the individual teet hand avoiding the creation of a 3 patterned effect in the teeth of the carding flats. A patterned effect of this nature causes the traversing grinding head to continually follow the same course or path in traversing the flats, thereby side grinding substantially the same teeth on each traverse thereby missing many of the teeth.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein embodiments of this invention are set forth by 'way of illustration and example.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view diagrammatically showing a carding machine with a set of revolving card flats in cooperative relation to a carding cylinder and a side grinding assembly in cooperative relation with the carding flats.

FIG. 2 is a sectional view taken on line 22 of FIG. 1, showing the side grinding assembly with the grinding head disposed in grinding relation to plurality of rows of wires on a carding flat.

FIG. 3 is a sectional view through the grinding head showing the thread follower on the grinding head in engagement with the cross thread of the screw shaft.

FIG. 4 is a fragmentary sectional view taken on line 44 of FIG. 2 illustrating one of the adjustable brackets for mounting the grinding assembly directly to the carding machine.

FIG. 5 is an end elevational view of the gear box showing the back plate with the screw shaft extending therethrough and having an end portion adapted to receive a crank or other means for manual positioning of the grinding head.

FIG. 6 is a sectional view taken through a single carding flat showing the relation of the abrasive disc of the grinding head to a row of wires on the carding flat.

FIG. 7 is comprised of FIGS. 7a, 7b, 7c and 7d, all illustrating the cooperative action between the wires on the carding flat and the flexible abrasive disc on the grinding head. FIG. 7a shows the abrasive disc disposed between adjacent rows of wire teeth on the carding fiat in a position for effecting a side grinding action on each of said rows. FIG. 7b illustrates the bending of the wires in that row as the pressure and abrasive action is increased due to the displacement of the grinding head. In FIG. 7c, the grinding disc has passed to the next row in a subsequent flat. FIG. 7d is a schematic plan view of the disc movement illustrated in FIGS. 7a, 7b, and 70.

FIG. 8 is a perspective view diagramatically showing the gear transmission system employed between the driven drum and the screw shaft.

FIG. 9 is a sectional view through the gear box of the grinding assembly.

FIG. 10 is a sectional view taken on line 1010 of FIG. 9 showing the gear transmission system substantially in an end elevational view.

FIG. 11 is a sectional view taken on line 1111 of FIG. 10 showing a means for uncoupling the gear transmission system.

FIG. 12 is a sectional view taken on line 1212 of FIG. 10 showing the mounting of one of the idler gears.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the reference numeral 1 broadly designates a carding machine embodying the features of this invention. The carding machine 1 includes a licker-in roller 2 which feeds a fibrous material from a supply 4 through feed rollers 6 to a carding cylinder 8. The carding cylinder 8 is disposed in cooperative relation with a revolving flat card 10 for aligning the fibers and moving the fibrous material to a doifer roll 12 from which the material is removed from the carding machine by a dolfing take oif device 14. The flat card 10, as illustrated, is conventional in nature, being comprised of a series of chain mounted flats 16 (FIGS. 6 and 7). The flats 16 each have on their outer surfaces card clothing, illustrated herein, as wire teeth or bent wires 18. As illustrated in FIG. 7d, the wires 18 of the flats 16 are disposed in a series of parallel, spaced rows extending generally in the direction of movement of the flat card 10. The rows of wires 18 defining passageways therebetween.

Side grinding assembly Referring to FIGS. 1 and 2, a side grinding assembly 2Q is illustrated mounted directly on the carding machine 1 in cooperative relation with the flat card 10 for side grinding or reneedling of the wires 18. The side grinding assembly 20 is comprised of a grinding head 22, a drum or tube 24, a cross-threaded screw shaft 26 and a speed transmission system 34. The grinding head 22 is operatively mounted on the drum 24 for rotation with said drum 24 and is reciprocally slidable longitudinally of the drum 24 by the cooperative action of the cross-threaded screw shaft 26. Referring to FIGS. 2 and 3, the drum 24 contains a keyway or slot 28 through which a thread follower 29 on the grinding head 22 extends for cooperative engagement in the cross thread of the screw shaft 26. The speed at which the grinding head 22 traverses the flats 16 is directly related to the speed differential between the drum 24 and the shaft 26. A decrease in speed differential decreases the rate of traverse of the grinding head 22 to the point where zero speed differential causes the grinding head to remain in a stationary position.

As illustrated in FIGS. 1 and 2, the drum 24 and grinding head 22 are driven at a desired speed by a motor 30. The motor 30 is preferably supported by a bracket 31 suitably mounted on the carding machine 1. As illustrated, the motor 30 is connected to the drum 24 by a chain drive system 32. The drum 24 and screw shaft 26 are interconnected by a speed transmission assembly 34 which provides a slight positive or negative speed differential between the drum 24 and the screw shaft 26.

Referring to FIGS. 2 and 3, the grinding head 22 is comprised of a body member 35 for retaining a plurality of abrasive disc members 37 in position. The abrasive disc members 37 may be of flexible rubber bounded by emery or the like defining a pair of opposed abrasive surfaces 39. As illustrated in FIG. 7, the peripheral edge portion 33 of the discs 37 are tapered providing an abrasive surface for hearing against the sides of the wires 18 disposed at approximately 30 degrees to the wires 18, whereby the tops of the wires may be suitably shaped by side grinding. This tapered edge of the disc both facilitates entry between the rows of teeth and the grinding of a taper on the teeth.

Referring to FIG. 4, an adjustable bracket 36 for retaining the grinding assembly 20 in relation to the bent wires 18 includes adjustable bracket members 38 and 40' having elongated adjustment slots 39 and 41 respectively for receipt therethrough of clamping bolts 43. An adjustment bolt 45 is suitably mounted through a protruding lug 47 on the bracket member 38 for providing minute adjustments of the grinding head inwardly and outwardly of the plane defined by the top of the wires 18.

Speed transmission assembly The speed transmission assembly 34 for transferring the rotational driving force of the drum 24 to the screw shaft 26 at a slight speed differential includes a gear transmission assembly or system 46. Referring to FIG. 8, the gear system 46 includes a first spur gear 48 suitably connected to the driven drum 24 and a second spur gear 50 suitably connected to the screw shaft 26 for transfer of a rotational driving force thereto as received through the gear transmission system 46. The gears '48 and 50 are interconnected by a pair of spur gears 52 and 54 mounted in fixed relation for rotation together about a shaft 56. The gear 52 is operatively coupled to the gear 48 on the drum 24 by a nonmetallic idler gear 58. The spur gear 54 is likewise operatively coupled to the spur gear 50 on the screw shaft 26 by means of a second nonmetallic idler gear 60. In this manner, the drum 24 drives the first gear 48 which in turn drives the idler gear 58 for driving the spur gear 52. The spur gear 52 in turn imparts a rotational driving force to the spur gear 54 for driving the idler 60 which in turn drives the spur gear 50 and thereby the screw shaft 26. This new and novel arrangement of gearing allows for a simple and efficient gearing assembly for producing a very slight speed differential between the to tational speeds of the drum 24 and the shaft 26.

The speed differential between the drum 24 and the shaft 26 is provided by employing gears in the transmission assembly 46 which vary slightly in their circumferential dimension thereby producing slight and controllable speed variations between the various gears. As an example, the various spur gears 48, 50, 52, and 54 are designated in FIG. 7 as having a specific number of equal dimensioned teeth. The number of teeth on a gear .is directly proportional to the circumference of that gear. Thus a gear with 6 teeth has a slightly larger circumference than a gear with 55 teeth. In this manner when the gear 48 is driven at a certain speed by the drum 24, the gear 52 being of a lesser circumference is thereby driven at a slightly greater speed providing a first stage speed increase in the transmission assembly 46. The second stage speed increase is then provided by the gear 54 which has a circumference slightly less than the circumference of the gear 52. It will be noted, however, that the gear 50 which is operatively connected to the shaft 26 has a circumference slightly greater than the circumference of the gear 54. This circumferential relationship between the

gears

54 and 50 provides a third stage speed decrease in the transmission system 46. Thus the gearing system 46 employs a three stage speed variable transmission wherein various combinations may be employed for arriving at a final rotational speed of the shaft 26 which is at a desired speed ratio to the drum 24 to thereby accurately control the speed of traverse of the grinding head 22. Speed differentials may vary in any desired manner such as a first stage decrease, a second stage decrease, and a third stage increase or a first stage increase, a second stage decrease, and a third stage increase.

The speed of traverse of the grinding head may be calculated by the following formula:

b0 T RP 1) In the above formula:

Thus using the example illustrated in FIG. 7 with R=500 P=1 /2, a=56, b=55, c=55, and d=54.

T=750 .00033 T=.2475 inch per minute Referring to FIGS. 9 to 11, the gear transmission system 46 is disposed in a housing or casing 62 having front and

back plates

64 and 66 respectively. The

plates

64 and 66 define a pair of aligned

apertures

68 and 70 respectively. The drum 24 and shaft 26 are each received through a friction reducing member 71 in the aperture 68 and mounted therein by a front bearing assembly 72. The drum 24 which is operatively coupled to the first spur gear 48 by a gear lock ring 74 terminates within the housing 62. The cross-threaded crew shaft 26, however, extends through the housing 62 and is received through a fric tion reducing member 75 in the aperture 70 in the back plate 66. The screw shaft 26 has a terminal end portion 76 suitably shaped, as for example, a rectangular cross section, for the releasable engagement of a crank or the like for manual operation of the screw shaft 26. The second spur gear 50 is coupled to the screw shaft 26 by a lock ring 78.

In the illustrated embodiment, the common shaft 56 about which the

gears

52 and 54 rotate in fixed relation is basically comprised of a gear stud 80 suitably mounted to the front plate 64, and having a friction reducing member 84 suitably mounted thereto and disposed circumferentially of the stud 80 to provide a surface on which the

gears

52 and 54 are free to rotate. The

gears

52 and 54 are locked in a fixed relative position by means of a lock ring 86.

The idler gears 58 and 60 are suitably mounted to the housing 62 in a coupled relation to the gear pairs 48, 52 and 50, 54 respectively. Referring to FIG. 12, the idler gear 58 is conventionally mounted on an idler gear arm 86 by means of the bolt 88 which retains a gear stud 90 on which the idler gear 58 rotates.

Referring to FIG. 11, the idler gear 60 is suitably mounted on an idler gear arm 92 by the bolt 94 which supports the idler stud 96 on which the idler gear 60 rotates. The idler arm 92 is mounted to the front plate 64 for rotational movement to thereby pivot the idler gear 60 in and out of cooperative engagement with the

gears

50 and 54. In this manner, when the grinding assembly 20 is not in operation, the gear transmission assembly 46 may be disengaged by pivoting the idler gear 60 to allow for a manual rotation of screw shaft 26 by a crank or the like. The idler arm is fixed in a desired rotational position by the force exerted thereon by a spring 98 retained in position by a spring retainer arm 100 which is suitably connected to the housing 62 by the bracket member 102.

This invention contemplates a flat driving means selectively operable to drive said card flats at any desired speeds including first speeds during the carding operation and second speeds specifically for side grinding. The second speeds are greater than said first speeds to thereby facilitate the side grinding operation. In this manner, this invention has achieved the flexibility of operation wherein the wires 18 may be side ground on their operative mounting on the carding machine 1 even during the carding process or operation. Preferably, however, by shutting down the carding operation for a period of minimum duration, the wires 18 may be quickly side ground by driving the flats on their operative mountings on the carding machine 1 at said second speeds. Thus, the duration of the period of equipment down time for side grinding is considerably reduced by the capability of this invention to grind the wires 18 Without removal of the flats 16 from the carding machine 1.

Referring to FIG. 1, the flat card 10 is preferably driven in cooperative relation with the carding cylinder or swift 8 in a conventional manner by a suitable power takeoff 104 from the main drive system 106 driven by a first motor 107 employed for operation of the carding machine 1. A conventional gear train and removable belt assembly 108 is employed in the power takeoff 104 whereby the speed of the flat card 10 may be controlled and the flat card 10 may be disengaged from the drive system 106. Any other suitable disengageable transmission may be substituted for the assembly 108.

Upon disengagement of power takeoff 104, the flat card 10 may then be driven at a greater rate of speed by a second drive means for the specific purpose of side grinding of the wires 18. As illustrated, the second drive means for the card flat 10 is the motor 30. The motor 30 is preferably connected to a drive sprocket wheel 110 on the card flat 10 by a suitable chain drive system 112 including a gear and clutch assembly 114. The

7 gear and clutch assembly 114 is employed to control the speed of the flat card and for disengagement of the drive system 112 when the power takeoff 104 is operatively connected to the card flat 10 during the carding operation.

Method of side grinding Referring to FIGS. 6 and 7, the progressive steps of the method of side grinding of carding flats as the carding flats are driven in their operative position on the carding machine is illustrated. Initially, the grinding head 22 is positioned relative to the Wires 18 with each, of the plurality of abrasive discs 37 located between a pair of adjacent rows of flat wires respectively such that the opposed abrasive surfaces 39 on the discs 37 tend to abrade each of the rows between which a disc 37 is disposed. Preferably, the outer edge of the discs 37 extend between the teeth about three quarters of the distance between the top of the teeth and the bend or knee of the teeth as shown in FIG. 6.

As the wire teeth 18 are moved past the grinding head 22 and the grinding head 22 is traversed normally to the direction of movement of the flats, the abrasive member 37 bears against the wires and each, the wires and disc, tend to bend, as illustrated in FIG. 7b. However, it is undesirable and damaging to the teeth for the discs to pass from, through or past one row of teeth to the adjoining row while the disc is on any particular flat. Instead the discs are caused to pass from one row to the next only in the space between the ends of the rows of teeth on one flat and the opposing ends of the rows of teeth on the adjacent fiat.

Normally there is provided about one disc for every two to three rows of teeth but this relationship may vary. The relationship between spacing of the discs and speed of traverse is random so that as the discs move back and forth across the carding flats they ultimately effect their grinding action between all or nearly all of the rows. It is undesirable to obtain what is termed a patterned effect where only certain of the wires in each of the rows are side ground leaving numerous wires untouched even with repeated passage of the grinding head across the flats.

The speed of traverse of the grinding head 22 in relation to the speed of movement of the card flats 16 to cause the discs to pass from one row of teeth to another only between the teeth on adjacent flats is critical to provide the proper degree of side grinding of the wires 18 without causing damage to the wires. If the grinding head is traversed at too great a rate, the discs will pass across the rows on individual flats and the teeth 18 will be damaged. In prior art devices where grinding discs passed across the teeth, the discs could not extend any appreciable distance between the teeth. Thus there was little or no side grinding and tapering of the teeth. There was only a minimal grinding of the top edge of the teeth.

In order to provide the desired grinding action, the abrasive members 37 are preferably driven at a speed between 500 to 1700 revolutions per minute.

When the carding flats 16 are being operatively driven in cooperative relation with the cylinder during the carding operation, the speed of said flats is in the range of about 8 inches per minute to about 11 inches per minute. In the aforestated situation, the grinding head is preferably traversed at a speed less than about 4 inch per minute in order to provide the desired movement of the abrasive members 37 through the rows of wires 18.

When the carding flats are being driven at an increased rate of speed by the second drive means, illustrated as the motor 30, the flats 16 are preferably moved at a rate of between about 10 feet per minute and about 15 feet per minute. When the flats are being so propelled by the motor 30, the desired rate of traverse may range from less than about inch per minute at a flat speed of about 10 feet per minute to about one inch per minute at a flat speed of about 15 feet per minute. It should be recognized,

however, that the flats 16 may be driven at any practical speed with the appropriate relation being developed between the flat speed and the speed of traverse. Thus the traverse of the grinding head would vary from less than about 4 inch per minute at a flat speed of 11 inches per minute to about one inch per minute at a flat speed of about 15 feet per minute. It is contemplated that the mountings which are normally employed on carding machines for flat movement will not permit flat speed in excess of about 30 feet per minute. Of course if flat speeds of 30 feet per minute are employed, the speed of traverse of the grinding head could be somewhat greater than one inch per minute.

The invention is not limited to the particular numerical relationships which have been discussed. The important consideration is that the ratio of flat speed to grinder traverse speed be such as to achieve the desired effect of grinding all of the rows of teeth on all of the flats without damage by causing the discs substantially never to pass across or through a particular row of teeth on a particular flat but to pass from one row to another and in the open spaces between the teeth on adjoining flats.

Operation of the illustrated embodiment In the illustrated embodiment the flats 10 and the side grinding assembly 20 are operatively driven or rotated by the motor 30 through the

chain drive systems

32 and 112. The rotational drive force imparted to the drum 24 is transmitted to the screw shaft 26 through the transmission system 34 in the manner previously discussed to drive the screw shaft 26 at a slight speed differential from that of the drum 24. The thread follower 29 on the grinding head extends through the keyway 28 and engages the cross threads of the threaded screw shaft 26 to cause the head 22 to transverse the flats 16 by the effect of the differential movement of the shaft 26 and drum 24. By controlling the magnitude of the speed differential between the drum 24 and the shaft 26, the rate of traverse of the grinding head 22 may be accurately controlled. The control of the magnitude of the speed differential is effected by the speed transmission assembly 46 in the manner previously discussed.

When the carding machine 1 is not in operation the power takeoff 104 to the card flat 10 may be disconnected at the gear box 108 and the card flat 10 operatively engaged to the motor 30 through the gear box 114 for driving the card flat 10 at an increased rate of speed. In this manner the wires 18 may be more quickly side ground.

It is a distinct advantage to drive both the flats and the side grinding assembly by the same motor or otherwise have them precisely synchronized. In this manner the proper speed relation may be maintained. Further, the starting and stopping of the flats and side grinder are thus always simultaneous. Substantial damage to the teeth may result where such starting and stopping are not simultaneous.

It is to be understood that while we have illustrated and described one form of our invention it is not to be limited to this specific form or arrangement of parts herein described and shown except insofar as such limitations are included in the claims.

We claim:

1. In a carding machine including a cylinder, a doffer, a plurality of card flats mounted on said machine for movement in an endless path in cooperative relation to said cylinder and means for driving said card flats, said flats having on their outer surfaces card clothing comprised of a plurality of generally parallel spaced rows of wire teeth, said rows of teeth extending generally in the direction of movement of said flats with open spaces being provided between the ends of the rows of teeth on adjacent flats, a grinding apparatus operatively mounted relative to said flats for grinding of said teeth while said flats are driven in their operative position on said carding machine comprising:

(a) a grinding head including a plurality of grinding discs each defining abrasive surfaces on the sides thereof, a portion of each of said discs being located between a pair of adjacent rows of said teeth and rotatable through a plane defined by the tops of said teeth, said rotation causing the abrasive surfaces to effect a grinding action on the sides of said teeth,

(b) means operatively connected to said grinding head for rotatably driving said grinding head and for reciprocally moving said grinding head across said flats transversely of said rows of teeth at a speed sufficiently slow related to the speed of movement of said flats such that the abrasive surface on each of said discs bears against the moving teeth of a particular row on a particular flat and substantially never passes across said row on that particular flat but passes from one row to another row only in said open spaces between the teeth on adjoining flats, said means for reciprocally moving said grinding head across said flats includes:

(1) a frame member,

(2) a hollow drum rotatably mounted on said frame member and extending across said flats transversely of said rows, said drum defining a slot longitudinally thereof for communication with its hollow interior,

(3) a cross-threaded screw shaft rotatably mounted in the hollow drum, said grinding head being slidably mounted on said drum and having follower means extending through said slot engaging the cross thread of the screw shaft, and

(4) transmission means operatively connecting the rotatable drum to the screw shaft for transmitting a rotational drive between said drum and said shaft with a slight speed differential whereby the grinding head is driven on said drum by said follower means at a desired speed while said head slides along said drum transversely of said rows, said transmission means includes a gearing system comprised of a first gear means operatively mounted on said drum and driven therewith, a second gear means operatively connected to said screw shaft and driven therewith and third and fourth gear means operatively coupled together and to said first and second gear means respectively providing first, second and third stage speed differentials between said first, third, fourth and second gearing means sequentially, two of said stages providing a speed increase and decrease respectively and the other of said stages providing a speed differential in the same direction as one of the other two stages.

2. The apparatus as recited in claim 1 wherein said first and second gear means are each spur gears having first and second circumferential dimensions and said third and fourth gear means comprise third and fourth spur gears operatively coupled together and to said first and second gear means respectively wherein the gears in each of the following pairs have slightly different circumferential dimension, said first and third gears, said third and fourth gears, and said fourth and second gears, two of said paired gears providing a speed increase and decrease respectively and the other pair of gears providing a speed diflerential in the same direction as one of the other two pairs of gears.

3. The apparatus as recited in claim 2 including means for mounting said third and fourth gears together for rotation in a fixed relation to each other and wherein said first gear is coupled to said third gear by a first idler gear and said fourth gear is coupled to said second gear by a second idler gear.

4. The apparatus as recited in claim 3 wherein one of said first and second idler gears includes releasable mounting means for retaining said idler gear in cooperative engagement in said transmission system including means for moving said idler gear out of cooperative engagement to open the transmission means permitting manual operation of the screw shaft for manual placement of the grinder head relative to the rows of teeth on the carding flats.

5. In a carding method employing a carding machine having a doifer, a cylinder, flats movable in an endless path in cooperative relation with said cylinder, said flats having on their outer surfaces card clothing including a plurality of spaced rows of flexible wire teeth defining a plurality of passageways, said rows and passageways extending generally in the direction of movement of the flats with open spaces being provided between the ends of the rows of teeth on adjacent flats, and a revolving grinding head in cooperative relation to said flats including grinding discs defining abrasive surfaces for said grinding the teeth on said flats including the steps of:

(a) moving the flats along said endless path about their operative mountings on the carding machine,

(b) locating a portion of each disc in respective passageways in engagement with the teeth of at least one of the rows of teeth defining said passageways and revolving said discs through a plane defined by the tops of said teeth to abrade the sides of said teeth,

(c) maintaining the discs in their respective passageways across at least one of said flats, and

(d) passing said discs laterally to other passageways only when the discs are in said open spaces between the ends of the rows of teeth on adjacent flats.

6. The method as recited in claim 5 wherein said flats are moved along said endless path at a first speed and wherein said discs are moved laterally of the movement path of said flats at a second speed, said second speed being related to said first speed to move each disc respectively along a row of teeth on at least one flat to abrade the side of said teeth and to pass the respective discs to other passageways only in the open spaces between the ends of the rows of teeth on adjacent flats.

7. The method as recited in claim 5 wherein each of said discs is passed through each of the open spaces between the ends of the rows of teeth on adjacent flats.

8. The method as recited in claim 5 wherein each of said discs is passed laterally to the next adjacent passageway only in said open spaces between the teeth on adjoining flats.

9. The method as recited in claim 5 wherein each of said discs is passed laterally to the next adjacent passageway at each of the open spaces between the teeth of each of the adjoining flats.

10. The method as recited in claim 5 wherein the flats are driven during the operation of the carding machine in cooperative relation with the cylinder and said grinding head is moved transversely of the rows of teeth on the flats at a speed of less than about 4 inch per minute.

11. The method as recited in claim 5 wherein the cylinder is stationary and the flats are driven separately from the carding machine at a speed in the range of about 10 feet per minute to about 15 feet per minute and said grinding head is moved transversely of said rows of teeth at a speed from less than about /1 inch per minute at a flat speed of about 10 feet per minute to about 1 inch per minute at a flat speed of about 15 feet per minute.

12. The method as recited in claim 5 wherein the flats are driven at a speed in the range of about 11 inches per minute to about 30 feet per minute and said grinding head is moved transversely of said rows of wires at a speed varying from less than about inch per minute at a flat speed of about 11 inches per minute to a speed slightly greater than 1 inch per minute at a flat speed of about 30 feet per minute.

13. In a carding method employing a carding machine having a doffer, a cylinder, flats movable in an endless path in cooperative relation with said cylinder, said flats having on their outer surfaces card clothing defining a plurality of spaced rows of flexible wire teeth extending generally in the direction of movement of the flats with open spaces being provided between the ends of the rows of teeth on adjacent flats, and a revolving grinding head in cooperative relation to said flats including grinding discs defining abrasive surfaces for side grinding the teeth on said flats including the steps of:

(a) moving the flats along said endless path about their operative mountings on the carding machine at a speed in the range of from about 11 inches per minute to about thirty feet per minute;

(b) locating a portion of each disc between adjacent rows of said teeth and revolving said discs through a plane defined by the tops of said teeth; and

(c) moving said grinding head across said flats transversely of said rows of teeth at a rate of speed varying from less than about A inch per minute at a flat speed of about 11 inches per minute to a speed slightly greater than 1 inch per minute at a flat speed of about 30 feet per minute.

14. The method as recited in claim 13 wherein the cylinder is stationary and the flats are driven separately from the carding machine at a speed in the range of about 10 feet per minute to about 15 feet per minute and said grinding head is moved transversely of said rows of teeth at a speed from less than about inch per minute at a flat speed of about 10 feet per minute to about 1 inch per minute at a flat speed of about 15 feet per minute.

15. The method as recited in claim 13 wherein the flats are driven during the operation of the carding machine in cooperative relation with the cylinder and said grinding head is moved transversely of the rows of teeth on the flats at a speed of less than about A inch per minute.

References Cited UNITED STATES PATENTS 8/1938 Great Britain.

DORSEY NEWTON, Primary Examiner