Cam mechanism for a circular knitting machine

Abstract

The invention discloses a cam device of a circular knitting machine, which is arranged on the periphery of a needle cylinder and has, in the direction of the needle cylinder, a tuck cam, a clearing cam, a drop cam and a knitting cam arranged from back to front. The tuck cam pushes the needles to the tuck height, the clearing cam further pushes the needles to the clearing height, and the drop cam lowers the needles. A needle separating cam is arranged between the drop cam and the knitting cam. The needles enter the needle separating cam directly or indirectly after leaving the drop cam, and then enter the knitting cam. The needle separating cam has a track of first rising and then falling, and its initial position is not lower than the tuck height of the needles, and its terminal position is the height suitable for entering the track of the knitting cam. The invention adds the needle separating cam between the drop cam and the knitting cam, and increases the number of feeders, and adjusts the front and back positions and the height of the feeders to form a reasonable separation angle to meet the requirement of high-speed knitting.

Description

Technical Field

[0001] This invention belongs to the field of knitting machinery technology, and particularly relates to circular knitting machines, and more specifically, to the triangular device of a circular knitting machine. Background Technology

[0002] Circular knitting machines include sock machines, underwear machines, and large circular knitting machines; this invention primarily refers to underwear machines. Its basic structure is a cylindrical needle cylinder with axially arranged needles on its outer wall. The needles move up and down along the needle grooves on the outer wall of the cylinder, simultaneously moving in a circular motion with the cylinder, driving the yarn to knit. To drive the up-and-down movement of the needles, a series of triangular devices are also configured around the cylinder. Several triangular devices are located outside the cylinder and can move radially or axially. Each triangular device has a different track on its inner surface close to the cylinder, and the needles run along these tracks, thus enabling the needles to move up and down. By controlling the position of each triangular device, different needle movement trajectories can be combined to meet the design requirements of the fabric.

[0003] In the cam mechanism of a circular knitting machine, the most basic is the loop-forming cam, which is positioned in the area roughly in phase with the shuttle, with its phase angle largely overlapping with that of the shuttle. It is used to form loops after the needle reaches the yarn feeding area and picks up the yarn. Since the cylinder rotates cyclically, the previous loop must be unhooked before loop formation. Therefore, the cam mechanism in this area is structured as follows: Along the direction of cylinder movement, from back to front, there are the loop-forming cam, the unhooking cam, the lowering cam, and the cam that form the loop. The loop-forming cam pushes the needle up to the loop-forming height, the unhooking cam further pushes the needle up to the unhooking height, and the lowering cam lowers the needle to a height suitable for entering the loop-forming cam track. This allows the needle to unhook the previous loop and begin feeding and forming the next loop.

[0004] The drawback of the existing technology is that after the needle passes the descending cam, it immediately enters the loop-forming cam's track. Therefore, the distance from the unwinding position of the previous loop to the feeding position of the next loop is short, resulting in a smaller circumferential length available for arranging the shuttles. Simultaneously, the yarn fed by the shuttle needs to form a reasonable separation angle with the shuttle in the tangential direction of the needle cylinder to prevent interference or tangling between the yarns of each shuttle, i.e., "yarn backing." Because the existing technology has a small feeding area available for arranging the shuttles and a small separation angle, it can only accommodate a limited number of shuttles, such as two to three, which is sufficient to meet the separation angle requirement. If more shuttles are used, the aforementioned yarn backing is highly likely to occur when the machine is running at high speed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a more reasonable triangular device for a circular knitting machine.

[0006] Therefore, the present invention adopts the following technical solution: the cam device of the circular knitting machine is set on the periphery of the needle cylinder. In the direction of needle cylinder operation, from back to front, there are tucking cam, untucking cam, dropping cam, and forming cam. The tucking cam pushes the knitting needle up to the tucking height, the untucking cam pushes the knitting needle up further to the untucking height, and the dropping cam presses the knitting needle down. The feature is that a dividing cam is also provided between the dropping cam and the forming cam. After the knitting needle leaves the dropping cam, it directly or indirectly enters the dividing cam, and then enters the forming cam. The dividing cam has a track that first rises and then falls, wherein its initial position is not lower than the tucking height of the knitting needle, and its end position is at a height suitable for entering the forming cam track.

[0007] Furthermore, the highest point of the dividing needle triangle track is not lower than the loop height of the knitting needle.

[0008] The phase angle of the circled triangle is located behind the phase angle of the shuttle.

[0009] The dividing needle triangle is fixedly set, the forming triangle can move up and down axially, and the gathering triangle and the uncoiling triangle can move in and out radially.

[0010] The aforementioned minute hand triangle has a closed track, meaning that there are track walls above and below the track to restrict the needle.

[0011] The needle of the knitting needle moves along the track of the triangle. Since the length of the knitting needle is fixed, the height of the track at a certain phase angle corresponds one-to-one with the height of the knitting needle. With the height of the triangle itself remaining constant, the height of its track can be defined by the height of the knitting needle. The terms "knitting loop height" and "knitting loop height" used in this invention refer to both the height of the knitting needle hook and the track height of the triangle at that time. Those skilled in the art can compare these terms using the same criteria based on the context.

[0012] The difference between the working process of this invention and the prior art is as follows: after the needle of the knitting needle is lowered by the drop needle triangle, it enters the track of the dividing needle triangle, runs a distance at a height higher than the gathering height, and then enters the loop forming triangle to perform the action of feeding yarn and forming loops.

[0013] This invention adds a dividing needle triangle between the descending needle triangle and the looping needle triangle. Essentially, the dividing needle triangle occupies the phase of the original looping needle triangle, thus shifting the looping needle triangle backward to a new phase angle; that is, shifting the yarn feeding area backward and offsetting it from the shuttle's area. From this analysis, it can be seen that the shuttle's position is one area, the yarn feeding position is another area, and whether yarn return occurs is a probabilistic issue. Therefore, the misalignment of the looping needle triangle and the shuttle described in this invention should be interpreted somewhat vaguely. Even if a few shuttles, such as a whole shuttle, have their phase angle within the phase angle area of ​​the looping needle triangle, or no more than a quarter of the shuttles have their phase angle within the phase angle area of ​​the looping needle triangle, the purpose of this invention can still be achieved.

[0014] Furthermore, the dividing cam raises the knitting needles from the tucking height to a position higher than the untucking height, then gradually lowers them, creating a height difference. This not only increases the circumferential feeding area but also expands the feeding area vertically. Because the shuttle height is fixed, but the height of the feeding needles varies, the angle of different yarns in the vertical direction will also be different. Therefore, by increasing the number of feeding shuttles, the separation angle can be adjusted by changing the shuttle's forward / backward and height positions to meet the requirements of high-speed knitting.

[0015] After testing, this invention is used in lingerie machines with a cylinder diameter of 13-22 inches. Even when running at a high speed of 100 revolutions per minute, it can still stably maintain the separation angle requirement for 5-6 shuttles, achieving precise yarn feeding. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a triangular device in the prior art.

[0017] Figure 2 This is a schematic diagram of the triangular device of the present invention.

[0018] Figure 3 This is a schematic diagram of the minute hand triangle. Detailed Implementation

[0019] See Figure 1 , Figure 2 By comparing these two images, the concept of this invention is easy to understand. The illustration unfolds the components arranged in a circular pattern into a planar view, and in the direction shown, the knitting needles move from left to right.

[0020] Figure 1In the prior art shown, the cam system sequentially includes a tucking cam 1, a loop-removing cam 2, a dropping cam 3, and a loop-forming cam 5. The knitting needle 15 passes through these cams, starting from the needle-starting height A and being pushed up to the tucking height B by the upper edge track 11 of the tucking cam, then pushed up to the loop-removing height C by the upper edge track 21 of the loop-removing cam, and finally pressed down by the lower edge track 31 of the dropping cam into the lower edge track 51 of the loop-forming cam. During this process, the knitting needle feeds the yarn from the shuttle 16 to the lowest position of the loop-forming cam, i.e., the loop-forming position. As can be seen in the figure, the phase of the shuttle largely overlaps with the phase of the loop-forming cam, specifically in the vertical direction. In this case, the area of ​​the yarn feeding region Q is relatively small, only accommodating three shuttles 16. In other words, only the three shuttles within this region can guarantee a reasonable separation angle at high speeds; shuttles outside this region inevitably experience yarn return.

[0021] Figure 2 and Figure 1 In comparison, the loop-forming triangle 1, loop-removing triangle 2, and drop-needle triangle 3 are the same as existing technologies. A dividing triangle 4 is added between the drop-needle triangle 3 and the loop-forming triangle 5. After the needle 15 leaves the drop-needle triangle, it indirectly enters the dividing triangle 4. Specifically, the jacquard piece (not shown in the diagram) raises the needle to the stand-up position 9, allowing it to enter the dividing triangle. The upper track 41 of the dividing triangle 4 pushes the needle higher than the loop-removing height, and then its lower track 42 lowers the needle into the lower track of the loop-forming triangle. Through this change, the phase of the shuttle and the phase of the loop-forming triangle are essentially non-overlapping, as shown in the diagram where they are essentially non-overlapping in the vertical direction, with the loop-forming triangle following the shuttle phase. At the same time, the area of ​​the yarn feeding area Q is relatively enlarged, which can accommodate six shuttles 16; it should be noted that the figure can only show the arrangement of the shuttles in the circumferential direction. In fact, there are height differences in the height direction of these shuttles, and they are arranged in a staggered manner. Therefore, in addition to the difference in the tangential direction, the separation angle of each yarn 00 also has an angular difference in the height direction, which further disperses the distribution of the separation angle.

[0022] See Figure 3 The dial 4 includes a mounting part 49, the opposite direction of which is close to the syringe barrel. A track 40 is located close to the syringe barrel, with track walls above and below it. The upper track wall exerts a downward force on the needle, hence it is called the lower track 42; the lower track wall exerts an upward force on the needle, hence it is called the upper track 41. The upper and lower tracks together constitute track 40, allowing the needle to move upward and then downward within it.

Claims

1. A cam mechanism for a circular knitting machine, disposed around the cylinder, comprising, from back to front, a tucking cam, a withdrawing cam, a lowering cam, and a loop-forming cam in the direction of cylinder movement; the tucking cam pushes the needle up to the tucking height, the withdrawing cam further pushes the needle up to the withdrawing height, and the lowering cam presses the needle down; characterized in that: Between the drop needle triangle and the loop forming triangle, there is also a dividing needle triangle. After the needle leaves the drop needle triangle, it enters the dividing needle triangle directly or indirectly, and then enters the loop forming triangle. The dividing needle triangle has a track that first rises and then falls. Its initial position is not lower than the loop height of the needle, and its end position is at a height suitable for entering the loop forming triangle track.

2. The triangular device of the circular knitting machine as described in claim 1, characterized in that: The highest point of the dividing needle triangle track is higher than the loop height of the knitting needle.

3. The triangular device of the circular knitting machine as described in claim 1, characterized in that: The phase angle of the circled triangle is located behind the phase angle of the shuttle.

4. The triangular device of the circular knitting machine as described in any one of claims 1-3, characterized in that: The dividing needle triangle is fixedly set, the forming triangle can move up and down axially, and the gathering triangle and the uncoiling triangle can move in and out radially.

5. The triangular device of the circular knitting machine as described in claim 4, characterized in that: The aforementioned minute hand triangle has a closed track, meaning that there are track walls above and below the track to restrict the needle.

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