US3765068A

US3765068A - Process and apparatus for the stufferbox crimping of yarns

Info

Publication number: US3765068A
Application number: US00162066A
Authority: US
Inventors: P Rietjens
Original assignee: Akzona Inc
Current assignee: Akzona Inc
Priority date: 1970-07-14
Filing date: 1971-07-13
Publication date: 1973-10-16
Anticipated expiration: 1990-10-16
Also published as: GB1351648A; DE2133764A1; NL7010429A; FR2101625A5

Abstract

Process and apparatus are disclosed for threading in a yarn crimping device such as a stuffer crimper wherby discharge of yarn from the device is detained during initial threadup an amount of yarn is present in the crimping chamber to effect sufficient crimp.

Description

United States Patent Rietjens Oct. 16, 1973 [5 PROCESS AND APPARATUS FOR THE 2,617,603 11/1952 Griset 57/34.5 x STUFFERBQX CRIMPING 0F YARNS 2,704,430 3/1955 Harris 57/34.5 3,526,023 9/1970 Mertensm 28/l.7

Inventor: Pierre L. L. M. RietjensQArnhem,

Netherlands Assignee: Akzona Incorporated, Ashville,

N.C. Filed: July 13, 1971 Appl. No.2 162,066

Foreign Application Priority Data July 14, 1970 Netherlands 7010429 US. Cl. 28/1.7, 28/72.14 Int. Cl. D02g 1/12 Field of Search ..28/1.7, 72.14; 57/345 References Cited UNITED STATES PATENTS Griset 57/345 X FOREIGN PATENTS OR APPLICATIONS 257,817 10/1967 Austria 28/1.7

Primary Examiner-Louis K. Rimrodt AttorneyFrancis W. Young [57] ABSTRACT Process and apparatus are disclosed for threading in a yarn crimping device such as a stuffer crimper wherby discharge of yarn from the device is detained during initial threadup an amount of yarn is present in the crimping chamber to effect sufficient crimp.

6 Claims, 3 Drawing Figures Patented Oct. 16, 1973 3,765,068

INVENTOR.

P. L'.L. M. RIETJENS fww. 7M

ATTORNEY PROCESS AND APPARATUS FOR THE STUFFERBOX CRIMPING OF YARNS The invention relates to a process for the stufferbox crimping of yarns, threads, or tows, in which the material to be crimped is forced with the aid of feed means into one or successive, communicating chambers of a crimping apparatus in which during normal operation a wad of crimped material is formed, and the crimped yarn is discharged at the end of the chamber(s), a signalling device being provided which responds to a supply of crimped material in the chamber(s), and that during the threading in of the crimping apparatus the crimped material may temporarily be discharged via a suction device.

The invention also comprises an apparatus for carrying out the above process.

A process of the type indicated above may be considered known from the British Patent Specification No. 1,049,953. During normal operation the yarn is forced against a wad or supply of yarn already crimped. At its discharge end the stuffing chamber is partly closed by a hinged flap which is loaded by a weight whose magnitude partly determines the magnitude of the stuffing pressure in the stuffing chamber. After the yarn has left the stuffing chamber, it enters a connecting buffer chamber whose discharge opening is partly closed by a lightly loaded flap. The discharge end of the buffer chamber and the flap are substantially transparent and on either side of the buffer chamber there are provided a light source and a light-sensitive pick-up, respectively. This photoelectric measuring device forms part of a control system," known in itself, for the stufferbox crimping process. This control system so operates that upon detection by the photoelectric pick-up of a sufficiently large wad of crimped material, a signal is given for increasing the rate at which the yarn is discharged from the buffer chamber. As soon as the photoelectric pick-up detects an insufficient amount of crimped material in the buffer chamber, a signal is provided for reducing the rate at which the yarn is discharged from the ing apparatus and by meansof a suction device very rapidly discharged temporarily to a collecting device. As a result of the high discharge rate, the material to be treated is pulled through'the chambers of the-crimping apparatus substantially as a straight, uncrimped thread. Since in that case no wad of crimped material is formed in the stuffing chamber, no crimp can be imparted to the yarn, so that only uncrimpedyarn is produced during thread'in. In the further threading in the yarn is passed through the other parts of the machine and finally arrives at the rotating winding spool in order to form a package thereon. The threading in process is then completed and the yarnis wound on a spool at a normal speed while forming a package, so that in the stuffing chamber a wad of yarn is formed and after a short time also properly crimped yarn of normal quality is wound.

A disadvantage to this known method of threading in consists in that part of the yarn wound on the spool is non-crimped and must be regarded as waste. Use being made of high processing speeds, for instance, of 1.000 to 2,000 meters/minute, and each machine having a large number of processing points, the resulting amount of waste is fairly considerable. I

The invention has for its object to provide a process of the type described in the opening paragraphs which does not show the aforementioned drawback. The process according to the invention is characterized in that during threading in of the crimping apparatus the signalling device that normally controls the yarn discharge rate from the buffer chamber (as described above) is temporarily coupled to the suction device. In operation, the suction device is manually operated to threadin yarn material through the crimping apparatus and then, the discharge of material via the suction device is stopped until a sufficient amount of crimped material is present in the chamber(s). This may be done by using, for example, the signal from the photocell signalling device discussed above. In such an instance, the photocell device will sense when there is insufficient yarn material in the crimping or buffer chamber (depending on the number of in-line chambers) and the signal thus produced will activate a shut-off valve on the suction device until the photocell senses a sufficient amount of yarn material in the chamber. After sufficient material has accumulated in the chamber, the suction control shut-off valve will be de-activated, and the suction device will begin drawing a crimped yarn from the chamber. In this manner, an operator may thread-in a crimping chamber and go about his other responsibilities until crimped yarn is being drawn from the crimping chamber. Upon returning to the position, the operator may simply break the yarn going into the suction device and finish threading the yarn to a windup spool, thereby eliminating the uncrimped waste usually formed on the prior art packages.

A particularly simple process, in which the suction device is actuated by the vacuum produced .by compressed air, is according to the invention characterized in that the signalling device is so coupled to a supply valve for compressed air from the suction device that said valve remains closed until a sufficient amount of crimped materia is present in the chamber(s). If the signalling device comprises a photoelectric pick-up, the process according to the invention iswith advantage characterized in that upon detection of a sufficiently large amount of crimped material, the photoelectric pick-up provides a signal for opening the supply valve for compressed air. I i

The invention will be explained further with reference to the acompanying schematic drawing.' I

FIG. 1 shows an apparatus for'the spinning, drawing, stufferbox crimping, and winding of yarns.

FIG. 2 shows an embodiment of a stufferbox crimping apparatus on a larger scale.

FIG. 3 shows a cross-section along the line III-III in FIG. 2.

In FIG. 1 a bundle of freshly spun threads 1 leaves a spinbox 2 and is transported in the direction indicated by the arrow by means of the driven feed roller 3 with idler roller 4, whichhave a peripheral speed of, for instance, 400 meters/minute. When on the roller 3, the melt-spun polyamide yarn will have cooled down to a temperature of about 40 C. Subsequently, the yarn is passedto a pair of driven draw rollers 5 and 6, which are heated at a temperature in the range of to C. and have a peripheral speed of 1,600 meters/minute,

so that the draw ratio of the yarn is 4:1. In order to avoid slippage, the yarn is wrapped a few times both around the roller 3 and around the rollers 5 and 6. The drawn and pre-heated yarn is transported over a guide roller 7 and forced into the stuffing chamber by a pair of cooperating stuffing wheels 8 and 9 which rotate in opposite directions, the stuffing chamber being provided with a flap 12 which is loaded by a weight 11. After the yarn has left the stuffing chamber 10, it arrives in a buffer chamber 13 at the end of which there is provided a flap 15 which is only loaded by a light spring 14. On one side of the buffer chamber 13 there is positioned a light source 16 and on the other side there is a schematically represented photoelectric pickup 17. As is particularly apparent from FIG. 3, the stufferbox crimper is of the open type, which implies that the walls of the stuffing chamber and the buffer chamber are substantially formed by two

parallel plates

18 and 19. At the level of the light source 16 and the pickup 17, the chamber walls are transparent, so that the amount of yarn in the buffer chamber can be measured photoelectrically. The winding device 22 serves to withdraw the yarn from the buffer chamber 13 by way of the guide rollers and 21, the yarn being wound on a package 23 by means of a grooved drum 24.

The suction device 25 is to be displaced by hand and may be attached to the machine frame. The suction device 25 substantially comprises a supply line 26 for compressed air, in which line an air valve 27 is provided for starting and stopping the suction device. The compressed air produces a vacuum in an aspirator type housing 28 and a tube 29, as a result of which the yarn can be sucked into the tube 29. The sucked yarn and the compressed air are discharged through a tube 30 and, via a flexible tube, deposited in a known manner in a collecting vessel for waste material. Between the photoelectric pick-up 17 and the air valve 27 there is provided means 31 for temporarily conveying a signal from the photoelectric pick-up device 17 to the air valve 27. The air valve 27 may then be controlled by signals from the photoelectric pick-up device.

During the threading in the tube 29 of the suction device 25 is placed under the spinbox 2 and emerging threads from the spinbox 2 are sucked into the suction device by air from a supply 26 passing through air valve 27 to the aspirator housing 28.

Subsequently, the freshly spun yarn from spinbox 2 is passed, by the use of the tip of tube 29, over the feed roller 3 with idler roller 4 and over the rotating draw rollers 5 and 6, after which the yarn is passed over the guide roller 7 and between the stuffing wheels 8, 9 into the stuffing chamber 10 and the buffer chamber 13. The excess yarn during this part of the threading-in is captured by the suction device 25. Immediately after the yarn has passed through the stufferbox crimper, the discharge of yarn via the suction device 25 is stopped until a sufficient amount of crimped material is present in the buffer chamber. As soon as the photoelectric pick-up 17 detects a sufficient amount of crimped material in the buffer chamber, the pick-up 17 provides via the line 31 a signal for opening the air valve 27, upon which the suction device 25 is re-started. The suction device will then withdraw crimped yarn from the buffer chamber, which yarn is rapidly threaded in by passing it over the

guide rollers

20 and 21 to the winding device 22.

Within the scope of the invention, various modifications may be made. For instance, instead of a photoelectric signalling device, it is possible to use a pneumatic, mechanical, or differently operating signalling device. Instead of applying stuffing wheels for forcing the material to be treated into the stuffing chamber, use may be made of a medium under pressure, for example, steam. Moreover, the process according to the invention may be applied by means of widely varying stufferbox chambers, more particularly also in the case of a stufferbox crimping apparatus in which a supply of crimped yarn is collected and/or transported by a rotating wheel or a like transporting member.

What is claimed is:

1. Method for threading a crimping chamber in a continuous yarn process, comprising the steps of:

a. feeding yarn continuously from a yarn supply to a crimping device;

b. threading the yarn through the crimping device;

0. discharging the yarn from the crimping device to a temporary yarn waste collection system;

d. interrupting the discharge ofthe yarn to the waste collection system untilsufficient yarn has accumulated in the crimping device to crimp the yarn; and thereafter e. winding the crimped yarn into a package.

2. Apparatus for threading a crimping chamber in a continuous yarn process, comprising:

a. means for continuously feeding yarn to the crimping chamber; 7

b. means for feeding yarn through the crimping chamber;

c. a yarn sensing device responsive to yarn accumulation in the crimping chamber for controlling the amount of yarn in the crimping chamber;

(1. a suction device downstream of said crimping chamber for temporarily receiving yarn during threadup; and

e. connective means between said yarn sensing device and suction device for stopping said suction device until sufficient yarn has accumulated in the crimping chamber.

3. Apparatus for threading a stuffer crimping device in a continuous yarn process comprising feed means for the yarn to be crimped, at least one crimping chamber, a signalling device responsive to accumulated yarn in the chambers, and a suction device operative by the signal device to stop the discharge of material to the suction device until sufficient material is present in the crimping chambers for crimping.

4. Apparatus for threading a crimping chamber from a continuous yarn supply, comprising a yarn suction device movable relative to said crimping chamber for accepting yarn during the threading of the crimping chamber and means for automatically interrupting said suction device until sufficient yarn has accumulated in the crimping chamber to crimp the yarn.

5. The apparatus of claim 4 wherein the suction device interruption means comprises a sensing device attached to the crimping chamber to determine yarn accumulation in the crimping chamber and control means operative from said sensing device for interrupting said suction device until sufficient yarn has accumulated in the crimping chamber.

6. The apparatus of claim 5 wherein the sensing device comprises photoelectric means within the crimping chamber.

- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,765 O68 I Dated October :16 1973 Invent or(s Pierre L.- L. M. Rietjens- It is certified that error appears in the ahoveidentified patent and that said Letters Patent are hereby corrected as shown below:

In theyab'stract, line l, aft-er threadup; add ---until-v-- I so' that the abstract reads: 1

"Process and apparatus are disclosed for threading in-a yarn crimping device such as -a stuffer crimper whereby discharge of yarn from the device is detained during initial threadup until an amount of yarn is present in the crimping chamber to effect sufficient'crimp.

Signed and-sealed this 20th day of Au ust iwu.

(SEAL) Attest:

McCOY'M. GIBSON, JR; c. MARSHALL 'DANN Attesting Officer Commissioner of Patents FORM PO-IOSOHO-GS)

Claims

1. Method for threading a crimping chamber in a continuous yarn process, comprising the steps of: a. feeding yarn continuously from a yarn supply to a crimping device; b. threading the yarn through the crimping device; c. discharging the yarn from the crimping device to a temporary yarn waste collection system; d. interrupting the discharge of the yarn to the waste collection system until sufficient yarn has accumulated in the crimping device to crimp the yarn; and thereafter e. winding the crimped yarn into a package.

2. Apparatus for threading a crimping chamber in a continuous yarn process, comprising: a. means for continuously feeding yarn to the crimping chamber; b. means for feeding yarn through the crimping chamber; c. a yarn sensing device responsive to yarn accumulation in the crimping chamber for controlling the amount of yarn in the crimping chamber; d. a suction device downstream of said crimping chamber for temporarily receiving yarn during threadup; and e. connective means between said yarn sensing device and suction device for stopping said suction device until sufficient yarn has accumulated in the crimping chamber.