The present invention relates to a circular comb for combing machines with a segment-shaped basic element on which the individual needles (teeth) are located parallel to each other and are connected by pressure strips fastened to the basic element under pressure.
In modern combing technology, the teeth (needles) are no longer fastened to a barrette (or bar), but to a wire or strip-like needle carrier to which they are soldered, welded or glued. For fastening such needle strips to a circular comb in a known embodiment (e.g. German Patent DT-OS No. 2,002,020), wedge-shaped grooves are located on the outside circumference of the basic element at predetermined intervals. Needle strips are inserted into these grooves and are pressed by means of a wedge-shaped clamping strip against the webs of the basic element remaining between the grooves. The necessary pressure is achieved by a number of screws distributed in the lengthwise direction over the clamping strip. These screws are threaded into the basic element. Since the combs are relatively close together and the needle tips in the peripheral direction are only 8 mm apart at the outside circumference of the basic element, and since the clamping strips are tapering conically inward, only very small screws can be used for fasteners. The same applies with respect to the pressure screws for detaching the clamping strips from the basic element; additional threads for these must be located in the clamping strip. When replacing the needle strips, a large number of small screws must be unscrewed and tightened again; this requires a considerable expenditure of time.
It is also known in the art how to screw fasten the individual needle strips one after the other to the basic element of a circular comb. The first needle strip is placed on the outside of the basic element and fastened by means of a wedge-shaped strip through which the screws pass to engage the threads in the basic element. The needle strip is pressed between the basic element and the wedge-shaped strip. This procedure is repeated till the last needle strip of the segment is reached; it is followed by a final segment which is designed so that the circular comb can be mounted on the machine shaft. The manufacture of such a circular comb is expensive. Even greater is the disadvantage that the individual needle strips cannot be exchanged one for one. In the extreme case, all preceding needle strips of such a circular comb must be removed before the last needle strip can be detached and replaced. This results in extremely cumbersome shutdowns.
It is, therefore, an object of the present invention to simplify the fastening of the needle strip on the circular comb of a combing machine and to provide individual interchangeability of the individual needle strips, regardless of whether it is the first or the last or any other needle strip.
Another object of the present invention is to provide a circular comb arrangement which may be economically fabricated and maintained in service.
A further object of the present invention is to provide a circular comb arrangement, as described, which has a substantially long operating life.