United States Patent 3648554

Apparatus for cutting thread wound on a spool or bobbin into staple fibers including two or more circular knives arranged radially of the spool axis at equal intervals with reference to the spool circumference and with their axes or rotation in a single plane and means to hold a completely or partially wound spool while axially shifting or moving it between the circular knives for cutting engagement with the thread.

Arnold, Walter (Klingenberg, DT)
Wepner, Gunter (Neuhaaren, DT)
Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
28/295, 83/433, 83/435.17, 83/516, 83/596, 83/913, 83/924
International Classes:
D01G1/04; B65H73/00; (IPC1-7): B26D7/08
Field of Search:
83/433,425,437,516,517,596,913,924,169,171,11,12,54,51,569 28
View Patent Images:
US Patent References:
3173320Machine for separating irradiated fuel slugs from their jackets1965-03-16Dabernard et al.
3050928Converting continuous filament to staple fiber1962-08-28Sumner
2776711Machine for cutting moving web into particles1957-01-08Bas
2613425Bobbin stripping apparatus1952-10-14Whitaker
2427167Apparatus for cutting fibers1947-09-09Thompson et al.
2319198Apparatus for slitting and cutting conductors1943-05-18Barrans et al.
1954817Insulation stripper1934-04-17Jenkins
1693996Armature-insulation-cutting machine1928-12-04Baker
1366082Recovering components of exhausted dry-battery cells1921-01-18Knabe

Primary Examiner:
Yost, Frank T.
The invention is hereby claimed as follows

1. Apparatus for cutting spool would thread into staple fibers comprising:

2. Apparatus as claimed in claim 1 wherein said circular knives are mounted for adjustable movement radially of the spool axis.

3. Apparatus as claimed in claim 1 wherein nozzle means are associated with each circular knife to direct a cooling gas thereon in their direction of rotation.

4. Apparatus as claimed in claim 1 wherein said circular knives are operatively connected with rotating drive means which provide a turning direction of the knives at the point of cutting engagement which coincides with the direction in which said spool is axially shifted for said cutting engagement.

5. Apparatus as claimed in claim 1 wherein said means to axially shift the wound spool includes means to retract the empty spool to a loading position after the thread is cut therefrom.

6. Apparatus as claimed in claim 1 comprising at least four circular knives arranged at equal intervals sufficiently small to cut the wound thread into staple fibers of about 20 to 150 mm.

7. Apparatus as claimed in claim 1 wherein said means to hold said spool includes a vertically shiftable clamping means which is removably fastened to said spool.

Threads, yarns or filaments wound on spools are sometimes unsuitable for further processing because of an unsatisfactory quality or simply because the spool is only partially wound after a particular operation. In order to free the completely or partially thread wound spools from the wound material, a number of stripping devices have been suggested which are intended to cause a quick removal of the yarn or thread without damaging the spool (see, for example, U.S. Pat. Nos. 2,609,876; 2,613,425; English Pat. No. 705,281 and German Pat. No. 1,278,906). These references mention nothing concerning a further processing or satisfactory use of the waste yarn or cut threads obtained by rapid removal from the spool with the stripping device. Presumably the waste yarn or cut threads after stripping are present in a form which at best would be suitable only for preparation into a textile material after one or more intermediate stages before a spinning operation. In many instances, the waste yarn would be extremely difficult to handle in such further processing due to excessively long and tangled lengths of the cut threads.

The material wound on spools, even though its quality is not sufficient for further preparation as a continuous thread or yarn, does possess for the most part a quality sufficient for use in the production of fleeces or fillers. However, the preparation of a fleece or filler material requires the material to be in the form of staple fibers of certain lengths.

The primary object of the present invention is to provide a cutting and stripping apparatus or device which will cut the thread or yarn contained on completely or partially wound spools into staple fibers of the desired length for direct use in further processing, for example in the production of nonwoven fabrics, fleeces, fillers and the like. Another object of the invention is to provide a cutting apparatus for producing staple fibers from spool wound thread or yarn which is easily constructed and operated as well as being adaptable to various spool or bobbin sizes. Other objects and advantages of the invention will become apparent upon consideration of the following detailed description.

It has now been found, in accordance with the invention, that a very satisfactory production of staple fibers can be achieved from otherwise waste yarn or threads wound on spools by apparatus which includes means to hold a spool which is at least partially wound with thread; a plurality of rotatable circular knives mounted radially of the spool axis at equal intervals to one another such that the axes of rotation of the circular knives lie in a common plane; and means to axially shift the wound spool between said circular knives for their simultaneous cutting engagement with the wound thread. At least two and preferably at least four circular knives are required for most spool sizes, and it will be recognized that the cutting edge of each knife lies in a plane projecting radially through the spool axis. Also, it is preferable to provide rotating drive means operatively connected, e.g., by a drive shaft, to the circular knives to cause a turning direction of the knives at the point of cutting engagement which coincides with the direction in which the spool is axially shifted for cutting engagement.

Surprisingly, it has been established that the layers of thread or yarn on the wound spool are cut in an unobjectionable and uniform manner by the circular blades or knives which are positioned for simultaneous cutting engagement. The desired staple length of the fibers, which must generally be greater than 20 mm. but smaller than about 150 mm. for the production of a fleece or filler material, is obtained by distributing a suitable number of circular blades around the circumference of the spool.

It is especially preferred for purposes of the invention, to provide means for adjusting the circular blades in a radial direction to the spool axis. Through this arrangement, the cutting device can be adapted to any given spool diameter. Also, the reduction of the diameter of the wound spool which occurs during the cutting operation of the circular blades is accurately regulated and balanced by the radially adjustable displacement of the circular blades.

An additional embodiment of the apparatus according to the invention is directed to means for blowing a cooling gas such as air onto the circular knives, for example by means of nozzles arranged to force a jet of cooling air in the direction of rotation. By cooling the circular blades, the cutting speed can be considerably increased. Additionally, the stream of air separates the cut fibers or filaments from the cutting position and helps to deliver them into a collecting chamber or receptacle.

In an especially preferred embodiment of the apparatus according to the invention, provision is made that the shifting movement or axial displacement of the spool takes place vertically downwardly while the axes of the circular knives lie in a single plane which is horizontal. With this arrangement, the cut fibers fall under the influence of their own weight into a collection bin arranged below the cutting device.

One advantageous embodiment of the apparatus of the invention is illustrated in the accompanying drawing wherein:

FIG. 1 is a partly schematic and cross-sectional view of the cutting device, taken approximately through a vertically positioned central axis;

FIG. 2 is a top plan view indicating the arrangement of four circular knives around the spool in the cutting position; and

FIG. 3 is an enlarged top plan view of one circular knife and means for its radial adjustment.

The spool holder and cutting apparatus is installed in any suitable supporting means or framework 1. On top of the framework there is positioned a bilaterally loadable pneumatic lift cylinder 2, i.e., one which has a reversibly operated piston reciprocating in a conventional manner by means of a four-way valve system (not illustrated). On the piston rod 3 of the lift cylinder 2, there is fastened a positioning fixture or spool holding device 4. At the end 5 of this holding device 4, a conventional expandable chuck or the like can be removably inserted into the core of the hollow spool 7 which is completely or partially wound with a thread or yarn material 6. Depending upon the exact construction of the individual spool or bobbin, the holding fixture 4 can be adapted to receive an appropriate holding or clamping means of any conventional type provided that it securely holds the spool in place for axial movement during the cutting operation. Furthermore, it is possible to provide means to sequentially introduce a large number of spools into the cutting device in an automatic manner by means of a suitable spool feeding arrangement. Such additional refinement of the apparatus does not constitute a specific feature of the invention but does illustrate the manner in which the cutting device is readily adapted to large industrial operations. For infrequent cutting requirements or relatively short periods of operation, hand loading and removal of the spools is quite adequate and easily accomplished.

As illustrated in FIG. 1, the piston within the pneumatic lift cylinder 2 is located at its upper end position, so that the piston rod is almost completely retracted to a spool loading position. Below the holding device 4 and the attached spool 7, there are arranged four circular blades or knives 8 in a radial direction with reference to the spool axis and at equal intervals to one another. The circular knives 8 are rotatably driven around their axes 9 lying in a common horizontal plane. The axes 9 are pivoted on bearing supports which can also be positioned in a radial direction to the spool (not shown in FIG. 1). The circular knives 8 in addition to suitable drive elements are preferably enclosed by a housing 10 which contains a funnel-shaped opening 11 as an inlet or receiving means for the spool 7. The nozzles 12 are installed in the upper circumference of the housing 10 and are supplied over suitable feed lines 13 with cooling air which is directed onto the cutting edge of each knife, preferably so as to flow across both faces in their turning direction and toward the spool as it is being cut. Below the cutting assembly, there is positioned a collecting bin 14 to receive the cut staple fibers. The collecting bin 14 is advantageously constructed in the form of a wagon or cart which can be inserted into and removed from the framework 1.

For cutting the material 6 from the spool 7, the lift cylinder 2 is reversed from the upper spool loading position of the piston 3. Thereby, the spool 7 is moved vertically downwardly as indicated by the arrow, whereby the material 6 is simultaneously engaged and cut by the circular knives 8 arranged at equal intervals, the turning direction of the knives being shown by arrows. The cut fibers fall under the influence of their own weight and are also assisted by the stream of cooling air so as to be directed into the collecting bin 14. After the spool 7 has passed through the circular knives 8, the lift cylinder 2 is again reversed to move the piston 3 and spool 7 vertically upwardly so as to return to the initial loading position shown in FIG. 1. After reaching this upper loading position of the piston 3 of the lift cylinder 2, the spool which is now free of the wound threads or yarn can be separated from the holding member 4 and another wound spool can be inserted. The above-described operation is then repeated after again reversing the lift cylinder 2 and its piston 3.

In the top plan view of FIG. 2, which includes only the four circular knives 8 with their drive shafts 9 and the spool 7, the radial and circumferential position of the knives 8 is more clearly shown with reference to the spool axis. The cutting edges of the knives are radially aligned at 90° positions around the spool axis and are preferably radially adjustable in the direction of the double-headed arrows with means to accurately fix each cutting edge so that it will not cut into the spool 7 but will practically completely cut through all of the wound thread material 6 indicated by the broken circular line. Each circular knife should be located at the same radial distance with reference to the spool axis in order to provide a simultaneous and equal cutting pressure.

FIG. 3 illustrates in greater detail an enlarged top plan view of one of the circular knives corresponding to the upper right quadrant of the assembly of FIG. 2. In order to permit a radial adjustment of the circular knife 8, its drive shaft 9 is supported on a bearing member 15 adapted to ride in a key slot 15a or the like located in a supporting rib 16 securely attached to the framework 1 and a horizontal mounting plate 17. A motor 18 or other drive means can also be slidably received on the mounting plate 17 so as to ride on a pair of tracks 19 parallel to the key slot 15a. By means of the hand-operated and threaded adjusting shaft 20, both the motor 18 and the attached drive shaft 9 and circular knife 8, can be easily and accurately adjusted to the desired radial position of the cutting edge of the knife. Any conventional locking means such as locking pins or screws can be used to hold the drive shaft and/or motor in a fixed position once the required adjustment has been made.

The lower shelf or bottom 21 of the housing 10 is preferably located below the mounting plate 17 to provide a substantially enclosed area for the motor or other drive means. In this respect, it is also possible to drive the circular knives by means of belts or gears on the drive shaft 9, but the disclosed embodiment has the advantage that all of the drive means are enclosed and contained within the housing 10 as well as the framework 1 to provide a compact cutting assembly. The framework 1 as shown in FIG. 3 is a substantially open structure composed of rigid vertical supporting beams, crossbars and similar members, since the housing 10 provides a sufficient enclosure to receive the wound spool and discharge the cut threads or fibers.

The circular knives are preferably operated at a relatively high speed which is uniform as between all of the knives. Each layer of the wound thread or yarn tends to become disengaged into staple lengths as the knife edges pass simultaneously therethrough, the inner cylindrical walls of intake 11 being adapted to guide and hold the partially cut layers of thread until they are discharged at the lower end.

The staple fibers obtained with the cutting device of the invention are surprisingly quite uniform, and after being collected, they can be immediately used as a fleece or filler material with very little if any processing. At the same time, the spools are recovered without damage and can be reused for other winding operations.