The present invention relates to a yarn loop density adjustment apparatus for circular knitting machines and particularly to a yarn loop density adjustment apparatus capable of adjusting individual cam on a saddle seat.
A circular knitting machine can control the yarn loop density of fabrics by adjusting the position of cams. The circular knitting machine has a plurality of cams to adjust the yarn loop density at different locations of a fabric.
Conventional techniques mostly aim to adjust the position of a single cam. For instance, R.O.C utility patent Nos. M251848 and M247597 granted to the Applicant disclose an adjustment method that has a regulation wheel turnable to drive a slider to adjust the position of a cam. The adjustment task is done manually. When the number of cams to be adjusted is great, to do adjustment takes a great deal of manpower and time. Human errors also are prone to occur. To remedy this problem, U.S. Pat. No. 5,511,392 discloses a method which has an elevating means to adjust the vertical position of a mounting plate, thereby saddle seats which hold cams and are located on the mounting plate can be moved up or down. While it can adjust the vertical positions of multiple cams, it cannot fine tune the yarn loop density of individual fabric zones.
U.S. Pat. No. 7,065,988 discloses a device aiming to alter stitch tightness of circular knitting machines. It is coupled with a movement adjuster connecting to a slider which is slidable on a cam box of a knitting machine and supports a knockover cam. The movement adjuster includes an actuator connecting to an adjustment cam, and may be driven to rotate the adjustment cam about its axis to a selected angle. The adjustment cam has an external active profile and two cam followers that are located on the slider. When the adjustment cam is driven by the actuator, the two cam followers adjust the cam position on the slider. It aims to adjust the position of a single cam without relying on moving up or down of the mounting plate. The actuator also provides driving to eliminate the uncertainty of human control and tedious operation. The adjustment cam is an eccentric cam in contact with the two cam followers. The contact positions require precise calculation and fabrication to ensure that the cam can provide accurate movement. Moreover, the adjustment cam is embedded deeply in the saddle seat. Its size and moving track range are restricted. Thus fabrication is difficult.
The primary object of the present invention is to provide positional adjustment for a single cam. It is structured simpler, and easier to fabricate or install in practice. To achieve the foregoing object the present invention provides a yarn loop density adjustment apparatus for circular knitting machines. It is installed on a circular knitting machine which has at least one needle to draw a knitting yarn. The yarn loop density apparatus includes a saddle seat coupled on the circular knitting machine and a driving means installed on the saddle seat. The saddle seat has a transmission mechanism driven by the driving means, a slider driven by the transmission mechanism and a cam fastened to the slider to guide movements of the needle. The slider and the saddle seat are interposed by an elastic element to keep the slider in contact with the transmission mechanism. The transmission mechanism has first teeth. The slider has second teeth corresponding to the first teeth. When the transmission mechanism is driven by the driving means, through mutual engagement of the first teeth and the second teeth, the slider can be driven to generate a moving displacement. By means of the mating teeth formed on the transmission mechanism and the slider the position of the cam can be precisely adjusted.
Another object of the invention is to prevent errors resulting from manual adjustment of the cam position, and maintain or adjust any time the cam position during operation of the circular knitting machine. To achieve this object the invention further includes a detection means to detect a driving condition of the driving means. The detection means generates a detection signal according to the driving condition of the driving means and inputs to a processing unit. The processing unit feedbacks an adjustment signal based on the detection signal to the driving means to adjust the driving condition thereof. The driving condition is the rotational speed of the driving means. The processing unit can preset a standard signal to determine the cam position and compare with the detection signal to output of the adjustment signal. Thus the cam can be moved to a preset position through the standard signal during operation of the circular knitting machine. Or the cam position may be changed during operation of the circular knitting machine to alter the yarn loop density to fabricate more versatile patterned fabrics.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
Please refer to
In this embodiment the driving means 30 is a serve motor to provide the driving source of the transmission mechanism 21. The transmission mechanism 21 is a gear set including a first gear 211 driven by the slider 22, a second gear 212 coupled with the driving means 30 and be driven thereof to drive the first gear 211. The first gear 211 has first teeth 211a formed thereon. The slider 22 has second teeth 221 mating the first teeth 211a. Moreover, the first gear 211 further has third teeth 211b. The second gear 212 has fourth teeth 212a mating the third teeth 211b. When the driving means 30 drives the second gear 212, through engagement of the fourth teeth 212a and the third teeth 211b, the first gear 211 is driven and rotates. Through engagement of the first teeth 211a of the first gear 211 and the second teeth 221 of the slider 22, the slider 22 is driven to generate a moving displacement.
To avoid not fully engagement resulting from tolerances of the second teeth 221 and the first teeth 211a that might cause a displacement error of the slider 22 driven by the driving means 30 through the transmission mechanism 21, an elastic element 222 may be interposed between the slider 22 and the saddle seat 20 to push the slider 22 in contact with the transmission mechanism 21. In this embodiment the saddle seat 20 has a track 24 to hold the moving displacement of the slider 22. The elastic element 222 has one end coupling with the slider 22 and other end coupling with the bottom 241 of the track 24. The elastic element 222 provides a force to push the slider 22 in contact forcefully with the first gear 211 so that the engagement of the second teeth 221 of the slider 22 and the first teeth 211a of the first gear 211 is closer and tighter. Thus when the transmission mechanism 21 rotates it can precisely drive the slider 22 to generate the moving displacement as desired.
Refer to
To facilitate interpretation and determination of the rotational position of the optical grid disk 41, the optical grid disk 41 further has an initial hole 412. And the detection means 40 has an initial spot sensor 44 corresponding to the initial hole 412. External light can trigger the initial spot sensor 44 through the initial hole 412 to allow detection to be performed to indicate that the optical grid disk 41 has finished one cycle of rotation or being located at the initial spot position.
Refer to
Before or during operation of the circular knitting machine equipped with the invention, enter the standard signal C that determines the position of the cam 23 through the input device 51 to the processing unit 50, and output the adjustment signal D to the driving means 30 to activate or adjust the driving condition of the driving means 30. The driving means 30 is a server motor. Based on the adjustment signal D the rotational speed or direction may be changed. The server motor drives the second gear 212 to rotate, and through the fourth teeth 212a and the third teeth 211b that are engaged, the rotation is transmitted to the first gear 211. Then through the engagement of the first teeth 211a and the second teeth 221, the slider 22 can be moved to the displacement desired. Referring to
As a conclusion, the yarn loop density adjustment apparatus for circular knitting machines of the invention can adjust the position of a single cam 23 to control the yarn loop density to fabricate fabrics with more versatile patterns. Through a simple gear set to drive the movement of the slider 22 the position of the cam 23 can be adjusted. It greatly reduces fabrication difficulty. In cooperating with the detection means 40 to detect the driving condition, the displacement of the cam 23 can be adjusted precisely. Thus the present invention provides a significant improvement over the conventional techniques.
While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.
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Number | Date | Country |
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247597 | Oct 2004 | TW |
251848 | Dec 2004 | TW |