US2719334A

US2719334A - Scavenger hood for pin drafting machines

Info

Publication number: US2719334A
Application number: US342531A
Authority: US
Inventors: Iii Andrew E Buchanan
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-03-16
Filing date: 1953-03-16
Publication date: 1955-10-04
Anticipated expiration: 1972-10-04

Description

A. E. BUCHANAN lll SCAVENGER HOOD FOR PIN DRAFTING MACHINES Filed March 16, 195.3I

2 Sheets-Sheet l ANDREW E. Bum/ANA n/,ZZZ

INVENTOR.

ATTORNEYS d s "1955 A. E. BUCHANAN m SCAVENGER HOOD FOR PIN DRAFTING MACHINES 2 Sheets-Sheet Filed March 16, 1953 @m N A: wm U 5 m M ATTDRNEYS United NStates Patent O SCAVENGER HOOD FOR PIN DRAFTING MACHINES Andrew E. Buchanan III, Charlotte, N. C.

Application March 16, 1953, Serial No. 342,531

11 Claims. (Cl. 19-139) This invention relates to scavenger or clearer mechanisms for textile machinery and, more especially, to an irnproved hood for scavenger mechanisms of the type used with pin drafting machines and which is particularly adapted to be used in lieu of the lower hood shown in my copending application entitled Scavenger Mechanism for Pin Drafting Machines, Serial Number 303,650, led August 1l, 1952, and of which the present invention is a continuation-in-part.

The scavenger mechanism disclosed in said co-pending application includes a lower hood or air-scoop which is provided with a curved wall which underlies and partially surrounds the bottom drafting roll. The pin drafting machine includes a transverse frame member spaced immediately beneath the bottom drafting roll as a result of which it is extremely difficult to position the lower hood or airseoop in proper relation to the bottom drafting roll.

lt is therefore the primary object of this invention to provide an improved air-scoop or hood for the lower drafting roll of a pin drafting machine or the like with an improved means for exerting upward pressure against the wall of the air-scoop to cause the brous or felt clearer elements carried thereby to resiliently bear against the lower drafting roll and the nip roll and wherein a cam is provided on the lower surface of the hood which engages a spring loaded plunger as the hood is slid into proper operative position relative to the lower drafting roll and which thereby serves as a guide during the course of positioning the lower hood or air-scoop beneath the lower drafting roll. The cam means on the lower surface of the lower hood is provided with a groove in which the upper end of the upwardly resiliently urged plunger tits when the hood is properly positioned and which thereby not only serves to exert upward pressure on the hood but also serves to maintain the hood in proper relation to the lower drafting roll and the nip roll disposed rearwardly thereof.

The hood is closed at opposite sides thereof, and at one end thereof, and is open at the other end thereof and a suction means is communicatively connected to the closed end of the hood so that any accumulations of lint and the like wiped oft the bottom roll by the wipers associated with the hood will be sucked into the hood' and subsequently carried away from the drafting zone.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings in which- Figure l is a fragmentary elevation showing a portion of the discharge or front end of a pin drafting machine, with parts broken away, and showing the improved scavenger hood in association therewith;

Figure 2 is a somewhat schematic longitudinal vertical sectional view through the pin drafting machine taken substantially along the line 2 2 in Figure l and showing the improved hood and its resilient pressure applying means disclosed beneath the lower or bottom drafting roll;

Figure 3 is an enlarged isometric view of the lower scavenger hood for the bottom drafting roll showing the top, one side and front of the hood;

Figure 4 is an enlarged fragmentary and somewhat schematic vertical sectional view taken substantially along the line 4-4 in Figure l and showing the hood and the pressure applying means therefor in elevation;

Figure 5 is an enlarged fragmentary vertical sectional view similar to the central right-hand portion of Figure 2;

Figure 6 is an enlarged isometric view of the resilient pressure applying means and the means for supporting the same, looking at the opposite side thereof from that shown in Figure 4 and showing the front end and top portions thereof;

Figure 7 is a View looking up at the bottom of the hood substantially in the direction of the arrow 7 in Figure 3 and showing the cam means provided thereon to permit ease in installing the hood.

Referring more specifically to the drawings and, particularly to Figure Z, the conventional pin drafting machine comprises a frame broadly designated at 10 which supports a driven endless belt or apron 11 for directing a plurality of slivers S from a plate 12 to a pin drafting mechanism including upper and lower groups of

faller bars

15 and 16, respectively, provided with respective upper and lower drafting pins 17 and 20, which extend downwardly and upwardly from the

respective faller bars

15 and 16. These sets of faller bars are driven by conventional means, not shown, so the upper faller bars 15 move in a rectangular path in a counterclockwise direction and so the lower faller bars 16 move in a :rectangular path in a clockwise direction. The

proximal faller bars

15 and 16 thus move forwardly and attenuate and parallelize the slivers in their course to the drafting rolls to be presently described.

The drafting rolls include an upper or top drafting roll or pressure roll 25 which presses the slivers against a driven lower or bottom drafting roll 26 and a nip roll 27, which is of substantially less diameter than either of the

drafting rolls

25 and 26 and is spaced slightly rearwardly of the nip of the top and

bottom drafting rolls

25 and 26. The nip roll 27 and the lower or bottom drafting roll 26 are usually fluted longitudinally about the periphery thereof and the periphery of the top drafting roll 25 is usually smooth.

It is thus seen that the slivers S are pulled forwardly by the top and

bottom rolls

25 and 26 and the nip roll 27 and subsequently pass through a suitable trumpet or trumpets 30, only one of which is shown. The trumpets 30 are supported on conventional trumpet supporting brackets 31 xed at their lower ends to a horizontal transverse frame member or portion 36 integral with a platform or plate 37 which forms a part of the frame 10. The slivers usually pass 'from the trumpets 311 into a suitable coiler 32 for coiling the same into a suitable receptacle or sliver can 33.

The lower or bottom drafting roll 26 is fixed on a shaft 40 journaled in bearing blocks 41 and 42 carried by a common transverse frame member 43 spaced slightly beneath the bottom roll 26. The frame 10 also includes a transverse frame member 44 which is spaced rearwardly of the frame member 43. The frame member 43, associated with pin drafting machines, is adjustable forwardly and rearwardly relative to theI frame member 44 and the improved means for applying upward pressure to the improved bottom hood is so arranged as to be readily mounted between the front and rear

transverse frame members

43 and 44, although the distance therebetween may be varied from time to time. The means facilitating forward and rearward adjustment of the front transverse frame member 43 is not shown and described,

since it is conventional and well known to those familiar with the art.

Reduced opposite ends of the top roll are journaled in the legs of an inverted substantially U-shaped bracket 45 which is mounted for vertical sliding movement in

projections

46 and 47 which extend toward each other from the respective bearing blocks or standards 41 and 42. A conventional spring means, including a compression spring 50 normally urges the bracket 4S downwardy to, in turn, bias the top roll 25 into engagement with the bottom roll 26 and the nip roll 27, or with the slivers passing therebetween. Since the spring 50 and the supporting means therefore are well known and are also clearly described in said co-pending application, a further detailed description thereof is deemed unnecessary, since they are not particularly pertinent to the present invention.

The scavenger mechanism disclosed in said co-pending application includes an upper hood or air-scoop 55 which is open at its rear end and which overlies the top roll 25. The front end of the upper hood or air-scoop 55 is provided with a tubular portion 56 which communicates with the interior of the hood 55 and to one end of which a flexible conduit or tube 57 is connected. The other end of the conduit or tube 57 is communicatively connected to a suitable means for inducing suction or negative pressure in the conduit 57 and for carrying away any lint or foreign matter which may be drawn into the pipe, conduit or tube 57 from the upper hood 55. In this instance, the means for inducing suction or negative pressure in the pipe or conduit 57 and the air-scoop or hood 55 is exemplified in a vertical duct 6@ connected to suitable suction means, not shown, and the closed lower end of which is suitably supported on the standard 42, by any suitable means such as an angle clip 62 and screws 63.

It is with the parts heretofore described that the irnproved lower air-scoop or hood, broadly designated at 70, is adapted to be associated.

The improved hood 70, with the exception of the cam thereon is of the same general construction as the lower hood or air-scoop 67 disclosed in said co-pending application. The lower air-scoop or hood 70 may be formed from a relatively thin material, such as sheet metal, plastic or the like, but is preferably cast from aluminum alloy, and comprises a curved rear or outer wall 71 which conforms substantially to the curvature of the periphery of the bottom drafting roll 26, but which has an internal radius substantially greater than the radius of the periphery of the bottom drafting roll 26 and is thus spaced from the bottom drafting roll 26. It will be noted that the free upper or rear edge of the curved wall 71 is disposed closely adjacent and immediately below the nip roll 27 and is also disposed closely adjacent the path of travel of the lower faller bars 16 as they move downwardly immediately rearwardly of the nip roll 27.

The curved wall 71 extends downwardly from adjacent said nip roll 27 and terminates in a tangential portion 72 which extends forwardly substantially horizontally from the curved wall 71 and is disposed at an angle of approximately 100 degrees from the free end of the curved wall portion 71 relative to the axis of the bottom drafting roll 26.

The tangential portion 72 extends forwardly beyond the vertical plane of the bottom drafting roll 26 and then curves upwardly to form a substantially three-quarter-circular portion 73 which may also be termed a tubular portion open at the rear surface thereof. The threequarter-circular portion 73 forms a relatively short upper or inner wall 74 (Figure 5) spaced inwardly from the inner surface of the tangential portion 72 of the outer curved wall 71.

It will be noted that this upper or inner wall 74 is preferably curved to conform substantially to the curvature of the periphery of the bottom drafting roll 26, but is spaced therefrom and has a resilient wiper element 75 thereon which curves outwardly and is secured 4 t to the substantially three-quarter-circular portion 73 of the lower hood 70, by any suitable means such as a rigid bar 76 and bolts 77.

The small upper wall 74 of the lower hood 70 is relatively short thus defining an opening at the inner portion of the hood 70 which is also dened by spaced

side walls

80 and 81. It will be observed in Figures 2, 3, 4, 5 and 7 that the outer edges of the

side walls

80 and 81 of the hood 70 are shaped to conform to the curvature of the outer wall 71 and the portion 72 thereof. The inner edges of

said walls

80 and 81 are shaped to conform substantially to the periphery of the bottom drafting roll 26, but are preferably of slightly greater radius than the drafting roll 26.

The inner edge of the

side walls

80 and 81 are each provided with a curved ilange 82 to which a suitable air-sealing element 83 is adhesively or otherwise secured. This air-sealing element 83 may be made from cloth, felt or any other' desired resilient material and, in actual practice, a strip of velvet material has been utilized for this purpose.

It will be noted that each of the flanges 82 terminates at one end thereof at the inner or rear edge of the wiper element 75 and terminates, at the other end there of, short of the radial plane of the free end of the outer wall 71 of the lower hood or air-scoop 70. However, each of the

side walls

80 and 81 has a relatively small tab or ear 85 extending outwardly therefrom which is provided for supporting opposite ends of a nip roll wiper supporting bar 86. This bar 86 spans the distance between the

side walls

80 and 81 and is suitably secured to the tabs 85. The Wiper support bar 86 defines an oriice or air inlet 90 in the free end of the hood or air-scoop 70; that is, the end thereof remote from the substantially three-quarter-circular portion 73, and through which air is drawn by means to be presently described.

The bar 86 is substantially rectangular in cross-section and has polished, rounded upper and lower edges. An improved wiper for the nip roll 27 is formed from a tube 91 made from a soft or resilient material such as rubber, felt, leather or the like, and snugly surrounds the bar 86 and serves as a movable wiper element. The wiper element 91 normally bears against the pcripheries of the nip roll 27 and the bottom roll 26. The tube, from which the wiper element 91 is made, is preferably circular `before being applied to the bar 86, so it is forced out of its normally cross-sectional configuration when applied to the bar 86. Thus, the wiper element 91 is retarded from rotation on the bar 91, through frictional contact therewith, and, in actual practice, the wiper element 91 rotates through contact with the bottom roll 26 and the nip roll 27, but at a slower peripheral speed than the rolls 26 and 27. This causes the wiper element 91 to be worn uniformly throughout its perimeter, rather than being worn excessively along its length at any one point. More especially, rotation of the tubular wiper element 91 causes accumulations of lint on the element 91 to be constantly fed from the nip roll 27 into the air stream, so the lint will not be enabled to accumulate to such an extent as to close the air inlet 90 and thereby require that the machine be stopped periodically for removing lint from the air inlet 9i?.

Now, the nucleus of the present invention resides in improved means to maintain the

wipers

75 and 91 of the lower air-scoop or hood 7) in resilient engagement with the lower drafting roll 26 andthe nip roll 27. To this end, i have provided an upwardly biased hood retaining pin 10i) which extends at an angle, as best shown in Figures 4, 5 and 6, and normally seats in a groove 101 formed in the lower surface of a cam member 102 suitably secured to, or integral with, the curved wall 71 of the lower hood 70.

The outer surface of the cam member 102 is formed with a substantially parabolic curve and preferably tapers to inlinity at its upper end, which upper end is substantially lush with the upper edge of the wall 71 delining the air ingress opening 90. The upwardly biased retaining pin 100 which preferably has a slightly rounded upper end, extends downwardly and rearwardly from a point rearwardly of the bottom roll 26 and at an angle substantially radially of the bottom roll 26 and is mounted for longitudinal sliding movement in a sleeve or elongated guide member 104 whose upper portion is externally threaded for reception of an adjustment nut 105. The sleeve is adjustably secured to a plate 106 which forms the upper wall of a bracket broadly designated at 107.

The bracket 107 is shown as being substantially channel shaped or inverted U-shaped in cross-section, but may be a solid block, if desired. In order to adjustably secure the sleeve or guide member 104 to the plate 106 of the bracket 107, the medial portion of the plate 106 has a forwardly and rearwardly extending adjustment slot 110 therein penetrated by the lower portion of the sleeve or guide member 104.

The sleeve or guide member 104 is provided with a flange 111, which may be welded thereto or may be integral therewith, and this flange 111 necessarily extends at an angle relative to the longitudinal axis of the sleeve 104 and bears against the upper surface of the plate 106. The lower surface of the plate 106 is engaged by an irregularly-shaped washer or spacing member 112 which is slidably penetrated by the lower portion of the guide member or. sleeve 104 and the lower surface of which is engaged by a lock nut 113 threadably mounted on the lower end of the sleeve or guide member 104.

Thus, the lock nut 113 clamps the washer 112 against the lower surface of the plate 106 and the flange 111 against the upper surface of the plate 106 for securing the guide member or sleeve 104 in the desired adjusted position. The retaining pin 100 is normally urged upwardly to a predetermined position relative to the sleeve 104 by a compression spring 114 whose lower portion surrounds the upper end of the sleeve 104 and engages the upper surface of the nut 105. The upper end of the compression spring engages an abutment 115 which is shown in a form of a washer suitably secured to the retaining pin 100, adjacent the upper end thereof.

In order to limit upward movement of the retaining pin 100, the lower end thereof has a washer 116 mounted thereon which is engaged by a lock nut 117 threadably mounted on the lower end of the retaining pin 100. rThus, the position of the upper end of the locking pin 100 may be varied relative to the bracket 107 as desired.

Now, the bracket 107 is provided with side walls or anges 120 and 121 which extend downwardly between the adjacent front and

rear frame members

43 and 44 and, since the upper surface of the front frame member 43 is normally disposed on a higher level than the upper surface of the rear frame member 44, the front edge of the plate 106 terminates substantially ush with the front edges of the

side walls

120 and 121. However, the bracket 107 is supported by both of the

frame members

43 and 44 and, therefore, the plate 106 has a rearwardly projecting portion 122 integral therewith which rests upon the frame member 44. The front portion of the plate 106, being disposed on a lower level than the level of the upper surface of the frame member 43, has an angle clip 123 suitably secured thereto, as by welding, the horizontal flange of which extends forwardly beyond the front end of the plate 106 and rests upon the front frame member 43.

In order to clampingly secure the bracket 107 between the

frame members

43 and 44, and to also accommodate variations in the spacing between the

frame members

43 and 44, the

side walls

120 and 121 have respective outwardly projecting

ears

124 and 125 integral therewith which are threadably penetrated by respective set

screws G l

126 and 127. Thus, the flanges 'or

walls

120 and 121 of the bracket 107 may be dropped into position between the

frame members

43 and 44, as the portion 122 of the plate 106 engages the upper surface of the frame member 44, and the horizontal portion of the angle clip 123 engages the upper surface of the frame member 43. Then, the

set screws

126 and 127 may be tightened against the front surface of the frame member 44 to thereby force the front edge of the plate 106 and the llanges 120 and 121 of the bracket 107 against the rear surface of the frame member 43 and to thereby lock the bracket 107 in position between the

frame members

43 and 44.

Now, the cam 102 is particularly provided to facilitate ready installation of the lower hood or air-scoop 70 and to also facilitate quick removal thereof from association with the bottom drafting roll 26. In the course of installation of the hood or air-scoop 70, the operator grasps the three-quarter-circular portion 73 thereof and, since the distance between the upper end of the pin and the bottom drafting roll 26 is less, or substantially the same as, the distance between the free end of the cam member 102 adjacent the air ingress opening 90 and the opposite surface of the nip roll wiper element 91, it is evident that the hood 70 may be readily inserted with a circular motion while the nip roll wiper element 91 is moved in sliding engagement with the periphery of the bottom drafting roll 26. lt will be noted that the cam 102 gradually increases in thickness from the upper free end thereof downwardly and thus causes the retaining pin 100 to gradually recede into the guide member or sleeve 104 or, in other words, causing the same to be moved downwardly in the sleeve 104 to cause the same to resiliently urge the hood 70 upwardly so the

wipers

75 and 91 are resiliently urged into engagement with the respective rolls 26 and 27.

Now, as stated in said co-pending application, upon excessive accumulations of lint and other foreign matter collecting at the wipers 75 and/or 91, the corresponding portion of the hood 70 is caused to move away from the roll 26 sufficiently to permit the masses or clots of fibers and the like to be carried into the hood 70 and subsequently carried away from the hood through the conduit 93. It is thus seen that the hood 70 may pivot in either direction about the upper end of the locking pin 100 and, with a little practice, the position of the locking pin 100 may be so adjusted as to exert the required amount of pressure on the

wiper elements

75 and 91 toward the respective rolls 26 and 27 It is thus seen that l have provided an improved hood wherein a cam is provided in association with a retaining pin and the cam being so shaped as to facilitate ready installation or removal of the hood 70 from association with the bottom drafting roll 26. Also, the distance between the upper end of the retaining pin 100 and the bottom drafting roll 26 may be varied either by adjusting the lock nut 117 to vary the amount of pressure exerted by the compression spring 114 Ior by loosening the lock nut 113 and adjusting the sleeve 104 forwardly or rearwardly in the slot of the bracket 107, as desired. The amount of upward pressure exerted by the retaining pin 100 may be adjusted by varying the position of the nut 105.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specic terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

l. In a drafting machine having a set of drafting rolls including a top roll, a bottom roll and a relatively small nip roll disposed closely in advance of the nip of the top and bottom rolls and wherein textile fibers pass successively over said nip roll and said bottom roll; the

combination of a hood having a wall underlying said bottom roll, one edge of said wall being disposed closely adjacent and beneath the nip roll, the portion of the wall remote from said one edge extending beneath the bottom drafting roll and being curved over upon itself, a wiper element carried by the portion of the hood whose wallV is curved upon itself and engaging said bottom roll, a wiper support bar carried by said hood and spaced inwardly from said one edge of said wall, an endless wiper element mounted for frictional rotational movement on said support bar and engaging the proximal lower portions of the nip roll and the bottom roll, a cam member projecting outwardly from said underlying wall and extending from a point adjacent said one edge thereof downwardly toward the other end of said wall, an upwardly biased pin disposed beneath said hood and engaging said cam member, and said pin extending at an angle substantially radially of the axis of said bottom roll.

2. In a drafting machine having a set of drafting rolls including a top roll, a bottom roll and a relatively small nip roll disposed closely in advance of the nip of the top and bottom rolls and wherein textile fibers pass over said bottom roll and nip roll; the combination of a hood having a wall underlying said bottom roll, one edge of said wall being disposed closely adjacent and beneath the nip roll, the portion of the Wall remote from said one edge extending beneath the bottom drafting roll and being curved over itself, a wiper element engaging said bottom roll and being carried by the portion of the hood whose wall is curved upon itself, a wiper support bar carried by said hood and spaced inwardly from said one edge of said wall, an endless wiper element mounted for frictional rotational movement on said support bar and engaging the proximal lower portions of the nip roll and the bottom roll, a cam member projecting outwardly from said underlying wall and extending from a point adjacent the said one edge thereof downwardly toward the other end of said wall, an upwardly biased pin disposed beneath said hood and engaging said cam member, said pin extending at an angle substantially radially of the axis of said bottom roll, and means for adjusting the pin relative to the bottom roll.

3. In a drafting machine having a set of drafting rolls including a top roll, a bottom roll and a relatively small nip roll disposed closely in advance of the nip of the top and bottom rolls and wherein textile fibers pass successively over said nip roll and said bottom roll; the combination of a hood having a wall underlying said bottom roll, one edge of said wall being disposed closely adjacent and beneath the nip roll, the portion of the wall remote from said one edge extending beneath the bottom drafting roll and being curved over upon itself, a wiper element carried by the portion of the hood whose wall is curved upon itself and engaging said bottom roll, a wiper support bar carried by said hood and spaced inwardly from said one edge of said wall, an endless wiper element mounted for frictional rotational movement on said support bar and engaging the proximal lower portions of the nip roll and the bottom roll, a cam member projecting outwardly from said underlying wall and extending from a point adjacent said one edge thereof downwardly toward the other end of said wall, an upwardly biased pin disposed beneath said hood and engaging said cam member, said pin extending at an angle substantially radially of the axis of said bottom roll, and means for varying the amount of upward pressure exerted by said pin.

4. In a drafting mechanism having top and bottom rolls, a curved scavenger hood underlying the bottom roll and provided with wipers on the upper surface thereof which engage said bottom roll, said drafting mechanism having first and second spaced frame members extending substantially parallel to the bottom drafting roll, said first frame member being disposed immediately beneath the bottom drafting roll; the combination of a cam member tixed on the lower rear portion of said hood, a bracket,

means ,clampingly securing said bracket between the first and second frame members at a point to one side of, and on a lower level than, the bottom drafting roll, an angularly disposed retaining pin extending substantially radially of the axis of said bottom drafting roll and being mounted for vertical sliding movement in said bracket, means for adjusting said pin toward and away from said bottom roll in said bracket, spring means normally urging said retaining pin upwardly against the cam member crried by said hood to thereby cause the wiper elements to resiliently engage the bottom drafting roll, means for varying the amount of pressure exerted by the compression spring on the pin and means for adjustably restraining upward movement of said pin.

5. In a drafting mechanism having top and bottom drafting rolls and also having a relatively small nip roll disposed in advance of the nip of the top and bottom rolls and over which strand material is adapted to pass in its course to the nip of the top and bottom rolls, the combination with a hood underlying the bottom drafting roll and having a wiper element engaging the front lower portion of the bottom drafting roll, of a wiper support bar disposed forwardly of the bottom drafting roll and beneath the nip roll, said wiper support bar being substantially rectangular in cross-section and being relatively thin and flat, one narrow edge of the support bar being disposed adjacent the proximal portions of the nip roll and bottom roll, the upper and lower narrow edges of said support bar being rounded, a resilient tube snugly encircling and frictionally engaging said wiper support bar, and said resilient tube being positioned so as to engage the proximal portions of the nip roll and the bottom drafting roll whereby rotation of the nip roll and the bottom drafting roll will cause rotation to be imparted to the resilient tube and the support bar will retard movement of the resilient tube so the rolls rotate at a greater surface speed than that of the resilient tube.

6. In a scavenger mechanism for pin drafting machines, said pin drafting machine having a set of drafting rolls including a bottom roll, a relatively small nip roll disposed rearwardly of the bottom roll and on a higher level than the axis of the bottom roll, said scavenger mechanism including a curved hood underlying the bottom roll and being provided with a pair of wiper elements thereon one of which engages the nip roll and the bottom roll at their proximal portions and the other of which engages the bottom roll at a point spaced substantially from the nip roll, said machine also having a first frame member spaced closely beneath the bottom roll, a second frame member spaced rearwardly from the first frame member; the combination of a curved cam member projecting outwardly from the hood, a bracket, means for clampingly securing the bracket between said first and second frame members, said bracket being spaced beneath the nip roll, an angularly disposed guide member adjustably secured in said bracket and extending substantially radially of the bottom roll, a retaining pin mounted for longitudinal movement in said guide member, resilient means normally urging said retaining pin into engagement with the cam member for maintaining the wiper elements in engagement with the corresponding rolls, means for varying the amount of upward pressure exerted on the retaining pin by the resilient means, and means for adjustably restraining upward movement of the retaining pin.

7. In a scavenger mechanism for pin drafting machines, said pin drafting machine having a set of drafting rolls including a bottom roll, a relatively small nip roll disposed rearwardly of the bottom roll and on a higher level than the axis of the bottom roll, said scavenger mechanism including a curved hood underlying the bottom roll and being provided with a pair of wiper elements thereon, one of which engages the nip roll and the bottom roll at their proximal portions and the other of which engages the bottom roll at a point spaced substantially from the nip roll, said machine also having a first frame member spaced closely beneath the bottom roll, a second frame member spaced rearwardly from the first frame member; the combination of a curved cam member projecting outwardly from the hood, a bracket, means for clampingly securing the bracket between said first and second frame members, a retaining pin movably disposed in said bracket and extending substantially radially of the bottom roll, resilient means normally urging said retaining pin into engagement with the cam member for maintaining the wiper elements in engagement with the corresponding rolls, and means for varying the amount of upward pressure exerted on the retaining pin by the resilient means.

8. In a scavenger mechanism for pin drafting machines, said pin drafting machine having a set of drafting rolls including a bottom roll, a relatively small nip rolldisposed rearwardly of the bottom roll and on a higher level than the axis of the bottom roll, said scavenger mechanism including a curved hood underlying the bottom roll and being provided with a pair of wiper elements thereon, one of which engages the nip roll and the bottom roll at their proximal portions and the other of which engages the bottom roll at a point spaced substantially from the nip roll, said machine also having a first frame member spaced closely beneath the bottom roll, a second frame member spaced rearwardly from the first frame member; the combination of a curved cam member projecting outwardly from the hood, a bracket, means for clampingly securing the bracket between said first and second frame members, a retaining pin movably disposed in said bracket and extending substantially radially of the bottom roll, and resilient means normally urging said retaining pin into engagement with the cam member for maintaining the wiper elements in engagement with the corresponding rolls.

9. In a drafting mechanism having at least one set of drafting rolls including a top roll, a bottom roll and a nip roll of relatively smaller diameter than the bottom roll disposed rearwardly of the nip of the top and bottom rolls, said drafting mechanism also having a first frame member spaced closely beneath and extending in substantially parallel relation to the bottom drafting roll, a second frame member spaced rearwardly from the first frame member and wherein the distance between the frame members may be adjusted, a curved hood underlying the bottom roll and having its rear portion curving upwardly and terminating in closely spaced relationship beneath the nip roll, a first wiper element carried by the hood and disposed adjacent the upper edge of said hood and engaging the lower proximal portions of said nip roll and said bottom roll and a second wiper element carried by said hood and engaging the lower front por tion of the drafting roll; the combination of a cam member projecting outwardly from the curved rear portion of said hood and extending downwardly from the upper edge thereof, said cam member being formed with a substantially parabolic curve on the outer surface thereof, a bracket having a horizontal plate portion and Yside walls, flanges extending downwardly from said side walls and adapted to be positioned between the first and second frame members, said plate portion on the bracket extending rearwardly beyond the anges and. being adapted to rest upon the second frame member, threaded members penetrating the flanges and adapted to bear against the front surface of the second frame member to thereby clamp the front surfaces of the anges of the bracket against the rear surface of the first frame member, an angularly disposed guide member penetrating said plate and being mounted for forward and rearward adjustment therein, said guide member extending at an angle substantially radially of the axis of said bottom drafting roll, a retaining pin mounted for longitudinal sliding movement in said guide member, spring means normally urging the retaining pin into engagement with said cam member, means adjustably restraining upward movement of the retaining pin, and means for adjusting the amount of pressure exerted by said spring means on the retaining pin whereby said cam facilitates ease in installing and removing said hood and also whereby said re taining pin causes the first and second wiper elements to resiliently engage the corresponding rolls,

10. In a structure according to claim 9, wherein the first frame member is disposed on a higher level than the second frame member, an angle clip carried by said plate portion and having its upper horizontal portion projecting forwardly beyond the front edges of the plate portion and said flanges whereby the horizontal portion of the angle clip rests upon said first frame member.

11. In a drafting machine having a set of top and bottom drafting rolls between which textile fibers pass; the combination of a hood having a wall underlying said bottom roll, one edge of said wall being spaced from said bottom roll, the portion of said wall remote from said one edge extending beneath said bottom roll and being curved upon itself, a wiper element engaging said bottom roll and being carried by the culved portion of said wall, means urging said hood toward said bottom roll comprising a cam member projecting outwardly from said underlying wall and extending from a point adjacent the said one edge thereof downwardly toward the other end of said wall, an upwardly biased pin disposed beneath said hood and engaging said cam member, said pin extending at an angle substantially radially of the axis of said bottom roll, and means for adjusting the pin relative to the bottom roll.

References Cited in the file of this patent UNITED STATES PATENTS 908,341 shipp Dec. 29, 190s 1,451,990 La Chapelle Apr. 17, 1923 2,446,839 Lee Aug. 10, 1948 FOREIGN PATENTS 13,799 Great Britain of 1902 393,494 France Dec. 23, 1908