The invention relates to a yarn feed system with electrical components and to a cable for making contact with such a yarn feed system.
Yarn feed systems are used in knitting machines or other textile machines for feeding a yarn to a yarn-consuming station, for instance, at a predetermined tension or in a prescribed quantity. The yarn feed systems draw the yarn from a bobbin and keep it in readiness on a drum for consumption by the yarn-consuming machine, or feed it to that machine. Such yarn feed systems are usually secured in relatively large numbers on a suitable mount, such as a so-called machine ring. For that purpose, they have a clamp. Besides the mechanical connection with the textile machine, such yarn feed systems generally also require an electrical connection so that existing electrical components can be connected.
From German Patent Disclosure DE-OS 21 48 653, a yarn feed system in the form of a yarn storage feeder is known, which has a yarn feed drum that is driven under the control of an electric motor. The drum and the motor are secured to a horizontally extending mount, which on its free end has a jaw-like clamp that is open at the bottom. A hook-like leg of this clamp has a clamping screw, whose axis is oriented transversely to the opening direction of the jaw. On the side facing the clamping screw, there are a plurality of contact pins, which have sharpened tips. The tips serve to pierce the insulation of a cable and make contact with the conductors present in the cable. The cable is a ribbon cable, which is disposed on a carrier or machine ring of rectangular cross section. The contacts, in at least one version, are supported for axial movement so that upon meeting the cable they can still be thrust backward somewhat.
In making contact, it is important that the contact pins securely meet the conductors that are concealed within the cable. The connection of a yarn feed system to a textile machine must therefore be made with care. The degree of care employed with the yarn feed system, however, cannot be determined in advance by the manufacturer of the yarn feed system.
It is the object of the present invention to provide a yarn feed system which can be properly connected mechanically and electrically to a textile machine in an especially simple, secure way.
Another object is to provide a cable which can be used with less vulnerability to error in creating a secure connection of the yarn feed system to a textile machine.
In carrying out the invention, the yarn feed system of the invention has a fastening clamp with contact pins. The contact pins are preferably disposed in stationary fashion. However, in some cases, it can be desirable for the contact pins to be axially movable instead.
The individual contact pin or contact pins (if there are more than one) have an associated guide element which guides the cable, particularly relative to the transverse direction of the conductor, in the insulation-piercing operation of the contact pins. The guide element preferably is adapted to the contour of the conductor. The conductor is formed for instance by a flat multi-cord cable of rectangular cross section. Accordingly, the guide element then has a jaw of approximately rectangular or even trapezoidal cross section, which corresponds to that of the flat multi-cord cable. The guide element is supported for longitudinal, but not transverse, movement to the contact pins, and as a result in the insulation-piercing operation it holds the cable so firmly that the contact pins securely meet the conductor or conductors of the cable.
In a first embodiment, the guide element is supported in stationary fashion relative to the main body, and the contact pins are supported for relative axial movement. In the position of repose, the contact pins are retracted far enough that they do not protrude into the interior of the guide element. Thus the cable can be introduced into the guide element by placing the yarn feed system on the machine ring. As the fastening screw is screwed in, first the yarn feed system is fixed as a result. As the fastening screw continues to be screwed farther in, by a deflection mechanism, the contact pins are thrust forward axially and thus pierce the cable. Alternatively, however, it is also possible for the contact pins to be activated by a separate actuating means, such as a lever, for instance via a cam drive or a separate screw; that is, the contact pins can be made to pierce into the interior, enclosed in jaw-like fashion by the guide element, so as to make electrical contact with the cable.
Alternatively, the contact pins can be stationary and instead the guide element can be movably disposed. This is particularly applicable to simple, robust embodiments. In that case, the guide element is preferably resiliently supported, and a spring means serves to tense the guide element into a receiving position. In the receiving position, it is located in front of the tips of the contact pins. As a result, it assures that the cable or some other conductor can be introduced into the guide element without becoming caught on the tips of the contact pins and thereby forced out of its desired position. Even if the cable is retained only relatively loosely on the machine ring or support rail of the textile machine, for instance by means of cable binders, correct contacting of the conductors of the cable is possible even if the yarn feed systems are installed somewhat carelessly.
The contact pins can be connected to various electrical components of the yarn feed system, such as an electrical switch, a sensor, a display device, a motor, a magnet coupling, or the like. The line that belongs to the textile machine and is contacted by the contact pins preferably leads to a central controller of the machine. Individual lines can be connected to a power supply. The lines can be signal lines and/or supply lines.
The contact pins preferably are insulation-piercing contacts in the form of needles. They can have a round or angular flat cross section, for instance, so that they can drill through a conductor. This is especially practical if the conductor is a flexible lead. It also is possible for the insulation-piercing contacts to be insulation displacement contacts, for instance, in the form of longitudinally slit contact tongues. These tongues pierce a cable insulation and receive the conductor in their slit, thereby contacting it.
A ribbon cable with one, two or more conductors can be used as the cable. The ribbon cable preferably has a rectangular cross section with rounded corners. In this case, the guide element assures that the contact pins will meet the conductors in the insulation-piercing operation. In a preferred embodiment of the cable, the cable has recesses on at least one side toward the insulation-piercing contacts, which guide the insulation-piercing contacts and the cable relative to one another in the insulation-piercing operation. The recesses are, for instance, grooves disposed parallel to the conductors which may be on one flat side of the cable or in both opposed flat sides. With respect to a plane oriented radially to the conductor and perpendicular to the flat side, the grooves preferably are disposed centrally to that plane. The grooves may be assigned to some of the conductors or to all of the conductors. In a preferred embodiment of the cable, the cable has two thicker conductors, embodied as flexible leads, which for instance act as supply lines, along with one or more thinner flexible conductors, which serve for instance as a signal line. In that case, the flat sides of the cable are provided with grooves only in the region of the signal lines, and the outer contour of the cable otherwise hardly deviates from a rectangle.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:
While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention.
Referring now more particularly to
For supplying power to the signal lamp 16 and/or for signaling the state of the yarn feeler lever 13 and/or the yarn feeler lever 14, a flat multi-cord cable 17 is disposed on the machine ring 4. This cable is fixed to some extent to the machine ring 4 by cable binders, adhesive tabs, or the like.
The clamp 3 is formed by a jaw that is open at the bottom. The jaw includes a leg 18 which initially extends horizontally in a rectilinear extension of the main body 2 and then, is bent at a right angle, extending vertically downward. The leg 18 defines a jaw 19 whose vertical height is approximately the same as the height of the machine ring 4, and whose horizontal width is greater than the width of the flat multi-cord cable 17 and of the machine ring 4 together. In side view, the jaw 19 has an approximately rectangular contour. For firmly clamping the yarn feed system 1 to the machine ring 4, a clamping screw 21 is used, which engages a horizontally oriented threaded bore of the leg 18. The threaded bore and the clamping screw 21 are disposed approximately centrally in the jaw 19.
The flat multi-cord cable 17 is disposed on the side of the machine ring 4 remote from the clamping screw 21. Contact pins 22, 23, 24, 25 that can be seen in
The tips 26-29 of the contact pins 22-25 protrude into a jaw-like recess 36, whose size is slightly greater than the cross section of the flat multi-cord cable 17. The tips 26-29, however, do not protrude out of this recess 36. In the region of the contact pins 22-25, a guide element 37 is seated in a vertical chamber or slit area of the recess 36. The guide element 37, preferably made from plastic, has a jaw 41 defined at the top and bottom by two protrusions 38, 39 corresponding in size to the cross section of the flat multi-cord cable 17 and opening toward the clamping screw 21. Between the protrusions 38, 39, the guide element 37 has an essentially plane seating face 42, formed with horizontal bores 43, 44, 45, 46 for receiving the contact pins 22-25, as can be seen particularly from
The guide element 37, which is shown in
The yarn feed system 1 described thus far is installed on a machine ring 4 as follows:
For installation, the clamping screw 21 is first screwed out of the jaw 19 far enough that the jaw 19 is completely free. In this state, the yarn feed system 1 is placed with its clamp 3 onto the machine ring 4 from above. The flat multi-cord cable 17 is then located opposite the jaw 41 of the guide element 37, as seen in both FIG. I and
If the fastening screw 21 is now tightened still more, then the flat multi-cord cable 17 and the guide element 37, as shown in
A modified embodiment of the yarn feed system is shown in
In
A flat multi-cord cable 54 of this kind is especially well suited for piercing, both with and without a guide element 37. The grooves 71-74 guide contact pins that perform the piercing. Conversely, if the contact pins come to rest like the teeth of a comb in the grooves 71-74, then the flat multi-cord cable 54 is automatically positioned at the correct height with respect to the contact pins.
In the yarn feed system of
The yarn feed system 1 of
If it is to be installed on the machine ring 4, as shown in
Hence, in the embodiment of
From the foregoing, it can be seen that the yarn feed system 1 of the invention has a clamp 3 for fastening on a machine ring 4. Contact pins are disposed on the clamp 3 and serve the purpose of piercing the insulation of a flat multi-cord cable 17 retained on the machine ring 4. For positionally correct orientation of the flat multi-cord cable 17 before and during the insulation-piercing operation, a guide element 37 is used, which is supported movably on or at the clamp. In the vertical direction, it is preferably retained by a spring arm 49. On its flanks, the flat multi-cord cable 17 preferably has grooves, which can likewise serve to orient the flat multi-cord cable positionally correctly before and during the insulation-piercing operation. The tips of the contact pins are located in the grooves and thereby bring about the alignment of the flat multi-cord cable 17 or 54.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 18 931.9 | Apr 2003 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP04/02744 | 3/17/2004 | WO | 11/22/2005 |