Parent Case Data:
This application is a division of U.S. Pat. application Ser. No. 163,174, filed July 16, 1971.
This is a continuation-in-part of U. S. Pat. application Ser. No. 857,767, filed Sept. 15, 1969 now abandoned.
Claims:
That which is claimed is
1. A drafting system comprising: a first pair of rolls having a top roll and a bottom roll in nip forming engagement, a second pair of rolls having a top roll and a bottom roll in nip forming engagement and being operably associated with said first pair of rolls, a drafting cradle operably associated with said second pair of rolls, a scraper member pivotally connected to said drafting cradle and resting on the top roll of said first pair of rolls and means operably associated with said second pair of rolls and said scraper member to automatically and intermittently move said scraping member in a direction away from said top roll to allow the scraped lint, trash, etc., to fall off said top roll.
2. The structure of claim 1 wherein said means to automatically move said scraper member is a cam and follower.
3. The structure of claim 2 wherein said cam encircles the lower roll of said second pair of rolls and rotates therewith.
4. The drafting system of claim 1 wherein said scraper member portion has a cavity therein and includes arm members engaging said cavity to support said scraper member portions in position on said top roll of said second pair of rolls.
Description:
There are numerous devices on the market today directed to the cleaning of drafting systems in order to prevent lap ups and ends down but these devices do not attack the problem directly. The best time to prevent a lap up or an ends down is prior to the build up of the condition that causes the lap up or ends down. Therefore, the disclosed invention is directed to a device to prevent the accumulation of lint, trash, etc., on the rolls of a drafting system which causes the occurrence of a lap up or an ends down.
It is therefore an object of the invention to prevent the accumulation of lint, trash, etc., on the rolls of a drafting system.
Another object of the invention is to provide an efficient, inexpensive device to clean the lint, trash, etc., off of at least one roll of a drafting system to prevent the build up of fibers thereon.
Other objects and advantages of the invention will become clearly apparent as the specification proceeds to describe the invention with reference to the drawings, in which:
FIG. 1 represents a cross-sectional schematic view of the new and improved drafting system;
FIG. 2 is a view similar to FIG. 1 showing the scraper being raised relative to the top front roll;
FIG. 3 is a top view of the lower middle roll of the drafting system with the top rolls removed;
FIG. 4 shows the scraper member per se;
FIGS. 5-7 show various scraper modifications; and
FIG. 8 illustrates a modification of the top roll clearer shown in FIGS. 1-7.
Looking now to the drawings, and especially to FIGS. 1 and 2, a running mass of staple fibers "F" is passed in conventional manner successively between pairs of drafting rolls 10, 12, 14, 16, 18 and 20 with each of the middle pair of rolls 14 and 16 having an endless fiber control apron 22 thereabout. From the nip of front drafting rolls 18 and 20, the fiber "F" is twisted and taken up by a conventional ring and traveler bobbin spinning system (not shown).
As is well known in the art, a front roll lap occurs when fibers being drafted wrap around either of the rolls 18 or 20 causing the yarn end 24 to come down and in extreme cases, cause damage to the drafting apron 22 and the drafting cradle 26. Normally, a few fibers will lap the roll and then more and more accumulate and wrap around the roll to form the lap. To prevent this condition from occurring a scraper member 28 is provided in engagement with the top front roll 18.
The scraper member 28 is preferably molded from those plastics which are readily moldable and which have good stability and wear characteristics, such as for instance, Delrin acetal resin, nylon and Bakelite. In the preferred form of the invention, the scraper 28 is molded with three projections 30 and a cavity which has three corresponding elongated finger positions 32 which extend longitudinally through the scraper.
The scraper member 28 is held in position by a U-shaped wire member 34 which has inturned projections 36 which are inserted in holes 38 in the side walls 40 of the cradle 26 to pivotally mount the scraper 28. The bottom portion 42 of the U-shaped wire member 34 extends through the cavity of the scraper. Welded or otherwise secured to the wire member 34 is a cam follower portion 44 which extends outwardly and downwardly from the wire member for reasons hereinafter explained.
Snapped onto the lower middle roll between two drafting positions is a cam member 46. The cam member 46 has a diameter slightly less than the diameter of roll 16 to insure a snug fit so that the cam member 46 will rotate with the roll 16. It should be noted that the cam member is thicker in the middle than at the ends to insure proper contact with the cam follower portion 44.
OPERATION
As discussed previously, the cam 46 rotates with the middle lower roll 16. Upon each rotation of the roll 16, the cam 46 will rotate in the position shown in FIG. 2 and engage the cam follower 44 causing it to rotate in the clockwise direction. Rotation of the cam follower 44 in the clockwise direction will cause the wire member 34 to pivot in this direction. Pivotal movement of the wire member 34 causes the wire member 42 to raise up and engage the upper side of the elongated finger portion 32. As the wire member continues to pivot upwardly the scraper member 28 will rise upwardly away from the roll 18. As the scraper member rises, the scraper member will rotate in the clockwise direction since the inward projections 36 act against the bottom of the finger portion 32 like an eccentric shaft and the weight of the scraper member 28 will cause it to rotate as indicated in FIG. 2. As the scraper member 28 rotates in a direction opposite to the rotation of the top front roll 18 the front edge of the projection 30 will scrape lint, trash, etc., from the surface of the roll. As the wire member 34 reaches the extreme upward position the scraper 28, preferably, will be lifted off the roll slightly to allow the dislodged lint, trash, etc., to fall off the roll. As the cam 46 continues to rotate, the scraper member 28 will be lowered onto the roll 18 once again with two adjacent edges of two adjacent projections 30 resting on the roll. When the scraper member 28 initially comes to rest on the roll, the portion 42 will move downwardly to the centerline position of the scraper member 28 whereat the rotation of the roll 18 will cause the scraper member 28 to be moved to the position shown in FIG. 1 wherein the bottom of the finger portion 32 engages the wire member portion 42 ready for another cycle. Since the middle lower roll rotates continuously, it is obvious that the cam 46 will continuously raise and lower the scraper member 28 to allow the scraped lint, trash, etc., to fall away from the drafting area. It should be noted that the scraper 28 will scrape the roll in the position shown in FIG. 1 as well as when it has been lifted to the position shown in FIG. 2
FIGS. 5-7 show various configurations and shapes of the scraper member 28. FIG. 5 shows the projection 30 with a convex surface while FIG. 6 shows the projections 30 with a concave surface which will conform to the radius of curvature of the roll 18. FIG. 7 illustrates a projection 30 which has a flat surface.
FIG. 8 shows a modification of the top roll clearer shown in FIGS. 1-7, except, preferably, this clearer is molded from a suitable plastic such as that used for the scraper member 28. In the modified top roll clearer the scraper member 28 will be used to scrape the lint, trash off the top front roll of the drafting system.
The top roll clearer of FIG. 8 is generally similar to that of FIGS. 1-7 in that pins 50 are molded to the arms 52 and 54 and are inserted in holes 38 of the cradle 26 to pivotally mount the scraper 28 (not shown in FIG. 8). Molded to the front inside portion of the arms 52 and 54 are pins 56 which project into the hollow interior of the scraper member 28 to hold the scraper member 28 in operative position on the top front roll 18 of the drafting system. To hold the arms 52 and 54 in a fixed spaced relationship a support bar 58 is molded thereto. At the end of the curved portions 60 of the arms 52 and 54 are molded cam followers 62 which when engaged by the cam will pivot the top roll clearer upward. There are two cam followers 62 so that, depending on the particular spinning frame, the actuating cam can be located on one side or the other of the drafting system.
It is obvious that the herein disclosed improved drafting system provides for continuous cleaning of the drafting rolls of a drafting system to prevent the build up of fibers, trash, etc., to eliminate or alleviate the possibility of a lap up. The improved drafting system is simple in construction and can be provided with a minimum amount of capital expenditure per spindle.
Although I have described in detail the preferred embodiments of my invention, I contemplate that many changes may be made without departing from the scope or spirit of my invention, and I desire to be limited only by the claims.