Needle bed transverse moving device of double-color tufting machine

Abstract

The utility model discloses a needle bed traversing device of a double-color tufting machine, which comprises a needle bed and a tufting needle (3), the needle bed is formed by combining a first needle bed (1) and a second needle bed (2) which are horizontally arranged and mutually embedded together, the tufting needle (3) is vertically arranged on the first needle bed (1) and the second needle bed (2), and the tufting needle (3) is arranged on the first needle bed (1) and the second needle bed (2). A first guide plate (4) is fixedly mounted at one end or two ends of the first needle bed (1), a second guide plate (5) is fixedly mounted at one end or two ends of the second needle bed (2), and the first guide plate (4) and the second guide plate (5) are vertically arranged and are driven by a driving mechanism to transversely move in the horizontal direction. According to the double-color tufting machine, knitting wool or grass yarns with two colors can be planted on grey cloth or base cloth through a single tufting machine, a formed product has a double-color effect, the production efficiency is high, and the structure is simple.

Description

Technical Field

[0001] The utility model relates to a tufting machine for producing artificial turf, carpets, blankets, etc., in particular to a needle bed transverse movement device of a tufting machine, belonging to the technical field of textile equipment. Background Technique

[0002] Existing tufting machines for producing artificial turf, carpets, blankets, etc., especially tufting machines for producing artificial turf, such as a structure disclosed in Chinese Utility Model Patent ZL202021976763.7, which includes a fixed frame, a support frame, an electric telescopic rod and a tufting machine. A textile table is arranged on the left side of the inner cavity of the fixed frame, a fiber layer is placed on the top of the textile table, a base cloth is placed on the top of the fiber layer, the support frame is arranged on the right side of the inner cavity of the fixed frame, a roller is arranged on the top of the support frame, a textile thread is wrapped on the side wall of the roller, the electric telescopic rod is arranged on the right side of the top inner wall of the fixed frame, a hollow cylinder is arranged at the bottom of the electric telescopic rod, a linkage rod is inserted into the inner cavity of the hollow cylinder, a motor is arranged in the inner cavity of the fixed frame, the motor is connected with a turntable, a presser foot is arranged at the bottom of the linkage rod, the presser foot is located above the base cloth, and the tufting machine is arranged in the middle of the top inner wall of the fixed frame. The existing tufting machine has the following disadvantages in the actual production process. Since it uses a single needle bed to move up and down to drive the tufting needles installed on the bottom surface of the needle bed to implant flocking yarn or grass filaments on the blank or base cloth, during operation, the needle bed only moves up and down and does not move horizontally. The flocking yarn or grass filaments in the formed product are all of the same color. If the product requires two colors of flocking yarn or grass filaments, that is, to form a two-color effect, it is necessary to first uniformly implant one color of flocking yarn or grass filaments on the blank or base cloth on one tufting machine, and then go to another tufting machine to implant another color of flocking yarn or grass filaments. That is, secondary processing is required to form a two-color effect, which results in low production efficiency and high production cost of the product. Summary of the Invention

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a needle bed transverse movement device of a two-color tufting machine that can implant two colors of flocking yarn or grass filaments on a blank or base cloth by a single tufting machine, the formed product has a two-color effect, can greatly improve the production efficiency, and reduce the production cost.

[0004] To solve the above technical problems, the present utility model adopts a needle bed transverse movement device of a two-color tufting machine, which includes a needle bed and tufting needles. The needle bed is composed of a first needle bed and a second needle bed that are horizontally arranged and mutually embedded. The tufting needles are vertically installed on the first needle bed and the second needle bed. At one end or both ends of the first needle bed, a first guide plate is fixedly installed. At one end or both ends of the second needle bed, a second guide plate is fixedly installed. The first guide plate and the second guide plate are vertically arranged and driven by a driving mechanism to perform a transverse movement in the horizontal direction.

[0005] As a preferred embodiment of the present utility model, a plurality of first convex teeth and first grooves arranged at intervals are provided on the front side surface of the first needle bed. A plurality of second convex teeth and second grooves arranged at intervals are provided on the rear side surface of the second needle bed. The first convex teeth of the first needle bed are embedded in the second grooves of the second needle bed. The second convex teeth of the second needle bed are embedded in the first grooves of the first needle bed. The tufting needles are vertically installed on the first convex teeth of the first needle bed and the second convex teeth of the second needle bed, and the tufting needles installed on the first convex teeth and the tufting needles installed on the second convex teeth are on the same horizontal line.

[0006] As a preferred embodiment of the present utility model, at both ends of the first needle bed, a first guide plate is fixedly installed. At both ends of the second needle bed, a second guide plate is fixedly installed. The first guide plate and the second guide plate are both rectangular plates with a rectangular cross-section. A vertically arranged first guide groove is provided on the outer side surface of the first guide plate. A vertically arranged second guide groove is provided on the outer side surface of the second guide plate. The driving mechanism includes a motor, a swing rod, a pin shaft, and rollers. One end of the swing rod is installed on the output shaft of the motor. The pin shaft is installed at the other end of the swing rod. There are two rollers, which are respectively installed at both ends of the pin shaft, and the two rollers are respectively rollingly embedded in the first guide groove and the second guide groove.

[0007] As a preferred embodiment of the present utility model, at both ends of the first needle bed, a first guide plate is fixedly installed. At both ends of the second needle bed, a second guide plate is fixedly installed. The first guide plate and the second guide plate are both rectangular plates with a rectangular cross-section. A vertically arranged first guide groove is provided on the outer side surface of the first guide plate. A vertically arranged second guide groove is provided on the outer side surface of the second guide plate. The driving mechanism includes an electric cylinder, a connecting rod, a pin shaft, and rollers. One end of the connecting rod is connected to the telescopic rod of the electric cylinder. The pin shaft is installed at the other end of the connecting rod. There are two rollers, which are respectively installed at both ends of the pin shaft, and the two rollers are respectively rollingly embedded in the first guide groove and the second guide groove.

[0008] As a preferred embodiment of the present utility model, the first guiding groove and the second guiding groove are rectangular grooves, the roller is a bearing, and the roller is in sliding fit with the first guiding groove and the second guiding groove in the vertical direction.

[0009] As a preferred embodiment of the present utility model, a first guiding plate is fixedly installed at one end of the first needle bed, and a second guiding plate is fixedly installed at one end of the second needle bed. The first guiding plate and the second guiding plate are both concave plates with a concave cross-section. The first guiding plate includes a first inner plate and a first outer plate arranged in parallel. The first inner plate is fixedly connected to one end of the first needle bed. The second guiding plate includes a second inner plate and a second outer plate arranged in parallel. The second inner plate is fixedly connected to one end of the second needle bed. The driving mechanism includes an electric cylinder, a connecting rod, a pin shaft and a roller. One end of the connecting rod is connected to the telescopic rod of the electric cylinder. There are two pin shafts which are installed on the rod body of the connecting rod in parallel and at intervals. There are four rollers which are installed at both ends of the pin shaft in pairs and oppositely. The first outer plate of the first guiding plate and the second outer plate of the second guiding plate are respectively placed between the rollers arranged in pairs and in rolling fit.

[0010] As a preferred embodiment of the present utility model, the distance between the tufting needles installed on the first convex teeth is one needle pitch, and the distance between the tufting needles installed on the first convex teeth and the tufting needles installed on the second convex teeth is half a needle pitch.

[0011] As a preferred embodiment of the present utility model, upright first positioning holes and second positioning holes are respectively formed on the first convex teeth and the second convex teeth. The upper needle bodies of the tufting needles are inserted into the first positioning holes and the second positioning holes and fixed by set screws.

[0012] As a preferred embodiment of the present utility model, the first convex teeth are adapted in size and shape to the second grooves, and the second convex teeth are adapted in size and shape to the first grooves.

[0013] As a preferred embodiment of the present utility model, the cross-sectional shapes of the first convex teeth, the second convex teeth, the first grooves and the second grooves are rectangular, triangular, trapezoidal or dovetail-shaped.

[0014] After adopting the above structure, the present utility model has the following beneficial effects:

[0015] The needle bed of the tufting machine of the present utility model is composed of a first needle bed and a second needle bed which are horizontally arranged and fitted together. The tufting needles are installed on the first needle bed and the second needle bed. At one end or both ends of the first needle bed, a first guide plate is fixedly installed. At one end or both ends of the second needle bed, a second guide plate is fixedly installed. During operation, only the first color of yarn or grass thread is inserted into the tufting needles of the first needle bed, and at the same time, the second color of yarn or grass thread is inserted into the tufting needles of the second needle bed. By moving the first needle bed up and down, the first color of yarn or grass thread is implanted into the base fabric or backing fabric. After the implantation is completed, the driving mechanism drives the first guide plate and the second guide plate to move horizontally and drives the second needle bed to move horizontally to the working position of the first needle bed. Preferably, the second needle bed moves horizontally by half a needle pitch. By moving the second needle bed up and down, the second color of yarn or grass thread is implanted into the base fabric or backing fabric to form a two-color effect, so that the completed product has both the first color and the second color of yarn or grass thread. The present utility model greatly improves the production efficiency and reduces the production cost.

[0016] The present utility model uses a single tufting machine to implant two colors of yarn or grass thread into the base fabric or backing fabric to realize a product with a two-color effect, greatly reducing the manufacturing cost of the product, and having a simple structure and convenient operation. Brief Description of the Drawings

[0017] The following further details the specific embodiments of the present utility model in conjunction with the drawings.

[0018] Figure 1 It is a schematic structural diagram of the first embodiment of the needle bed horizontal movement device of the two-color tufting machine of the present utility model.

[0019] Figure 2 It is a schematic structural diagram of a needle bed in the present utility model.

[0020] Figure 3 It is a schematic structural diagram of a first needle bed in the present utility model.

[0021] Figure 4 It is a schematic structural diagram of the first guide plate fixedly installed at both ends of the first needle bed in the present utility model.

[0022] Figure 5 It is a schematic structural diagram of a second needle bed in the present utility model.

[0023] Figure 6 It is a schematic structural diagram of the second guide plate fixedly installed at both ends of the second needle bed in the present utility model.

[0024] Figure 7 It is a schematic structural diagram of a tufting needle in the present utility model.

[0025] Figure 8This is a schematic structural diagram of the second embodiment of the needle bed transverse movement device of the double-color tufting machine of the present utility model.

[0026] Figure 9 This is a schematic structural diagram of the third embodiment of the needle bed transverse movement device of the double-color tufting machine of the present utility model. Specific implementation manners

[0027] See Figures 1 to 9 A needle bed transverse movement device of a double-color tufting machine shown in the figure includes a needle bed and tufting needles 3. The needle bed is composed of a first needle bed 1 and a second needle bed 2 that are horizontally arranged and fitted together. The tufting needles 3 are vertically installed on the first needle bed 1 and the second needle bed 2. A first guide plate 4 is fixedly installed at one end or both ends of the first needle bed 1, and a second guide plate 5 is fixedly installed at one end or both ends of the second needle bed 2. The first guide plate 4 and the second guide plate 5 are vertically arranged and driven by a driving mechanism to perform a transverse movement in the horizontal direction.

[0028] As a preferred implementation manner of the present utility model, as shown in Figures 2 to 7 the figure, the first needle bed 1 is in a long strip shape and preferably has an inverted L-shaped cross-section. A plurality of first convex teeth 1a and first grooves 1b are arranged at intervals on the front side of the first needle bed 1. The second needle bed 2 is in a long strip shape and preferably has an inverted L-shaped cross-section. Preferably, the second needle bed 2 is symmetrically arranged with the first needle bed 1. A plurality of second convex teeth 2a and second grooves 2b are arranged at intervals on the rear side of the second needle bed 2. The first convex teeth 1a of the first needle bed 1 are fitted in the second grooves 2b of the second needle bed 2, and the second convex teeth 2a of the second needle bed 2 are fitted in the first grooves 1b of the first needle bed 1. The tufting needles 3 are vertically installed on the first convex teeth 1a of the first needle bed 1 and the second convex teeth 2a of the second needle bed 2, and the tufting needles 3 installed on the first convex teeth 1a and the tufting needles 3 installed on the second convex teeth 2a are on the same horizontal line A.

[0029] As a preferred implementation manner of the present utility model, as shown in Figures 1 to 6As shown in the figure, at both ends of the first needle bed 1, a first guide plate 4 is fixedly installed by bolts. At both ends of the second needle bed 2, a second guide plate 5 is fixedly installed by bolts. The first guide plate 4 and the second guide plate 5 are both rectangular plates with a rectangular cross-section. On the outer side of the first guide plate 4, there is a vertically arranged first guide groove 4a. On the outer side of the second guide plate 5, there is a vertically arranged second guide groove 5a. The driving mechanism includes a motor 6, a swing rod 7, a pin shaft 8, and a roller 9. The motor 6 is fixedly installed on the frame of the tufting machine, and the frame is not shown in the figure. Preferably, a speed reducer is provided at the front end of the motor 6. One end (the upper end as shown in the figure) of the swing rod 7 is fixedly installed on the output shaft of the motor 6 by bolts. The pin shaft 8 is installed at the other end (the lower end as shown in the figure) of the swing rod 7. There are two rollers 9, which are respectively installed at both ends of the pin shaft 8, and the two rollers 9 are respectively rollingly fitted in the first guide groove 4a and the second guide groove 5a.

[0030] As a preferred embodiment of the present invention, as Figure 8 shown in the figure, at both ends of the first needle bed 1, a first guide plate 4 is fixedly installed by bolts. At both ends of the second needle bed 2, a second guide plate 5 is fixedly installed by bolts. The first guide plate 4 and the second guide plate 5 are both rectangular plates with a rectangular cross-section. On the outer side of the first guide plate 4, there is a vertically arranged first guide groove 4a. On the outer side of the second guide plate 5, there is a vertically arranged second guide groove 5a. The driving mechanism includes an electric cylinder 10, a connecting rod 11, a pin shaft 8, and a roller 9. The electric cylinder 10 is fixedly installed on the frame of the tufting machine, and the frame is not shown in the figure. The electric cylinder 10 preferably adopts a servo electric cylinder of a servo motor. One end of the connecting rod 11 is connected to the telescopic rod of the electric cylinder 10 by a threaded connection. The pin shaft 8 is installed at the other end of the connecting rod 11. There are two rollers 9, which are respectively installed at both ends of the pin shaft 8, and the two rollers 9 are respectively rollingly fitted in the first guide groove 4a and the second guide groove 5a.

[0031] As a preferred embodiment of the present invention, as Figure 1 、 4 As shown in Figures 6 and 8, the first guide groove 4a and the second guide groove 5a are rectangular grooves. The roller 9 adopts a bearing, and the roller 9 is in sliding fit with the first guide groove 4a and the second guide groove 5a in the vertical direction.

[0032] As a preferred embodiment of the present invention, as Figure 9As shown in the figure, a first guide plate 4 is fixedly installed at one end of the first needle bed 1 through bolts, and a second guide plate 5 is fixedly installed at one end of the second needle bed 2 through bolts. Both the first guide plate 4 and the second guide plate 5 are concave plates with a concave cross-section. The first guide plate 4 includes a first inner plate 4-1 and a first outer plate 4-2 arranged in parallel. The first inner plate 4-1 is fixedly connected to one end of the first needle bed 1. The second guide plate 5 includes a second inner plate 5-1 and a second outer plate 5-2 arranged in parallel. The second inner plate 5-1 is fixedly connected to one end of the second needle bed 2. The driving mechanism includes an electric cylinder 10, a connecting rod 12, a pin shaft 8, and a roller 9. The electric cylinder 10 is fixedly installed on the frame of the tufting machine, and the frame is not shown in the figure. The electric cylinder 10 preferably adopts a servo electric cylinder of a servo motor. One end of the connecting rod 12 is connected to the telescopic rod of the electric cylinder 10 through a threaded connection. There are two pin shafts 8, which are installed on the rod body of the connecting rod 12 in parallel and at intervals. There are four rollers 9, which are installed at both ends of the pin shaft 8 in pairs. The first outer plate 4-2 of the first guide plate 4 and the second outer plate 5-2 of the second guide plate 5 are respectively placed between the rollers 9 arranged in pairs in a rolling fit. During operation, the electric cylinder 10 drives the first guide plate 4 and the second guide plate 5 to move horizontally left and right through the rollers 9 arranged in pairs on the connecting rod 12, thereby driving the first needle bed 1 and the second needle bed 2 to move horizontally left and right simultaneously.

[0033] As a preferred embodiment of the present invention, as Figures 2 to 6 shown, the distance between the tufting needles 3 installed on the first convex teeth 1a is one needle pitch W, and the distance between the tufting needles 3 installed on the first convex teeth 1a and the tufting needles 3 installed on the second convex teeth 2a is half a needle pitch W.

[0034] As a preferred embodiment of the present invention, as Figures 3 to 7 shown, vertical first positioning holes 1c and second positioning holes 2c are respectively formed on the first convex teeth 1a and the second convex teeth 2a. The upper needle body 3a of the tufting needle 3 is inserted into the first positioning holes 1c and the second positioning holes 2c and fixed by set screws, and the set screws are not shown in the figure.

[0035] As a preferred embodiment of the present invention, as Figures 2 to 6 shown, the first convex teeth 1a are adapted in size and shape to the second grooves 2b, and the second convex teeth 2a are adapted in size and shape to the first grooves 1b.

[0036] As a preferred embodiment of the present invention, the cross-sectional shapes of the first convex teeth 1a, the second convex teeth 2a, the first grooves 1b, and the second grooves 2b are rectangular, triangular, trapezoidal, dovetail-shaped, etc. Only the rectangular cross-section is shown in the figure, and other shapes are not shown.

[0037] As a preferred working mode of the utility model, refer to Figure 1 and 8 , thread or straw of the first color is threaded through the tufting needles 3 of the first needle bed 1, and thread or straw of the second color is threaded through the tufting needles 3 of the second needle bed 2. The first needle bed 1 moves up and down to implant the thread or straw of the first color onto the base fabric or backing fabric. At this time, it is preferred that the second needle bed 2 remains stationary. After the first needle bed 1 finishes implanting, the motor 6 drives the swing rod 7 to swing, so that the first guide plate 4 and the second guide plate 5 are simultaneously translated and drive the second needle bed 2 to be translated to the working position of the first needle bed 1. It is preferred that the second needle bed 2 is translated by half a needle pitch W, or the electric cylinder 10 drives the connecting rod 11 to be translated, so that the first guide plate 4 and the second guide plate 5 are simultaneously translated and drive the second needle bed 2 to be translated to the working position of the first needle bed 1. It is preferred that the second needle bed 2 is translated by half a needle pitch W. At this time, it is preferred that the first needle bed 1 remains stationary. By moving the second needle bed 2 up and down, the thread or straw of the second color is implanted onto the base fabric or backing fabric to form a two-color effect, so that the completed product has threads or straws of two colors at the same time.

[0038] After trial use, the utility model realizes that a single tufting machine implants threads or straws of two colors onto the base fabric or backing fabric, and the formed product has a two-color effect, high production efficiency, and a simple structure, achieving good practical effects.

Claims

1. A needle bed transverse movement device of a two-color tufting machine, comprising a needle bed and tufting needles (3), characterized in that: The needle bed is composed of a first needle bed (1) and a second needle bed (2) which are horizontally arranged and fitted together. The tufting needles (3) are vertically installed on the first needle bed (1) and the second needle bed (2). At one end or both ends of the first needle bed (1), a first guide plate (4) is fixedly installed. At one end or both ends of the second needle bed (2), a second guide plate (5) is fixedly installed. The first guide plate (4) and the second guide plate (5) are vertically arranged and driven by a driving mechanism to perform a transverse movement in the horizontal direction.

2. The needle bed transverse movement device of the two-color tufting machine according to claim 1, characterized in that: On the front side of the first needle bed (1), a number of first convex teeth (1a) and first grooves (1b) are arranged at intervals. On the rear side of the second needle bed (2), a number of second convex teeth (2a) and second grooves (2b) are arranged at intervals. The first convex teeth (1a) of the first needle bed (1) are fitted in the second grooves (2b) of the second needle bed (2). The second convex teeth (2a) of the second needle bed (2) are fitted in the first grooves (1b) of the first needle bed (1). The tufting needles (3) are vertically installed on the first convex teeth (1a) of the first needle bed (1) and the second convex teeth (2a) of the second needle bed (2). And the tufting needles (3) installed on the first convex teeth (1a) and the tufting needles (3) installed on the second convex teeth (2a) are on the same horizontal line.

3. The needle bed transverse movement device of the two-color tufting machine according to claim 2, characterized in that: At both ends of the first needle bed (1), a first guide plate (4) is fixedly installed. At both ends of the second needle bed (2), a second guide plate (5) is fixedly installed. The first guide plate (4) and the second guide plate (5) are both rectangular plates with a rectangular cross-section. On the outer side of the first guide plate (4), a vertically arranged first guide groove (4a) is provided. On the outer side of the second guide plate (5), a vertically arranged second guide groove (5a) is provided. The driving mechanism includes a motor (6), a swing rod (7), a pin shaft (8) and a roller (9). One end of the swing rod (7) is installed on the output shaft of the motor (6). The pin shaft (8) is installed at the other end of the swing rod (7). There are two rollers (9) which are respectively installed at both ends of the pin shaft (8). And the two rollers (9) are respectively rollingly fitted in the first guide groove (4a) and the second guide groove (5a).

4. The needle bed lateral shifting device of the two-color tufting machine according to claim 2, characterized in that: At both ends of the first needle bed (1), a first guide plate (4) is fixedly installed. At both ends of the second needle bed (2), a second guide plate (5) is fixedly installed. The first guide plate (4) and the second guide plate (5) are both rectangular plates with a rectangular cross-section. On the outer side of the first guide plate (4), there is a vertically arranged first guide groove (4a). On the outer side of the second guide plate (5), there is a vertically arranged second guide groove (5a). The driving mechanism includes an electric cylinder (10), a connecting rod (11), a pin shaft (8), and a roller (9). One end of the connecting rod (11) is connected to the telescopic rod of the electric cylinder (10). The pin shaft (8) is installed at the other end of the connecting rod (11). There are two rollers (9) which are respectively installed at both ends of the pin shaft (8), and the two rollers (9) are respectively rollingly fitted in the first guide groove (4a) and the second guide groove (5a).

5. The needle bed transverse movement device of the two-color tufting machine according to claim 3 or 4, characterized in that: The first guide groove (4a) and the second guide groove (5a) are rectangular grooves. The roller (9) is a bearing, and the roller (9) is in sliding fit with the first guide groove (4a) and the second guide groove (5a) in the vertical direction.

6. The needle bed transverse movement device of the two-color tufting machine according to claim 2, characterized in that: At one end of the first needle bed (1), a first guide plate (4) is fixedly installed. At one end of the second needle bed (2), a second guide plate (5) is fixedly installed. The first guide plate (4) and the second guide plate (5) are both concave plates with a concave cross-section. The first guide plate (4) includes a first inner plate (4-1) and a first outer plate (4-2) arranged in parallel. The first inner plate (4-1) is fixedly connected to one end of the first needle bed (1). The second guide plate (5) includes a second inner plate (5-1) and a second outer plate (5-2) arranged in parallel. The second inner plate (5-1) is fixedly connected to one end of the second needle bed (2). The driving mechanism includes an electric cylinder (10), a connecting rod (12), a pin shaft (8), and a roller (9). One end of the connecting rod (12) is connected to the telescopic rod of the electric cylinder (10). There are two pin shafts (8) which are parallel and spaced from each other and installed on the rod body of the connecting rod (12). There are four rollers (9) which are installed in pairs at both ends of the pin shaft (8). The first outer plate (4-2) of the first guide plate (4) and the second outer plate (5-2) of the second guide plate (5) are respectively placed between the rollers (9) arranged in pairs in a rolling fit manner.

7. The needle bed transverse movement device of the two-color tufting machine according to claim 2, characterized in that: The distance between the tufting needles (3) installed on the first convex teeth (1a) is one needle pitch (W). The distance between the tufting needles (3) installed on the first convex teeth (1a) and the tufting needles (3) installed on the second convex teeth (2a) is half a needle pitch (W).

8. The needle bed traversing device of the two-color tufting machine according to claim 2, characterized in that: On the first convex teeth (1a) and the second convex teeth (2a), there are respectively provided upright first positioning holes (1c) and second positioning holes (2c). The upper needle body (3a) of the tufting needle (3) is inserted into the first positioning hole (1c) and the second positioning hole (2c) and fixed by a set screw.

9. The needle bed lateral shifting device of the two-color tufting machine according to claim 2, characterized in that: The first convex tooth (1a) is adapted in size and shape to the second groove (2b), and the second convex tooth (2a) is adapted in size and shape to the first groove (1b).

10. The needle bed transverse movement device of the two-color tufting machine according to claim 2, characterized in that: The cross-sectional shapes of the first convex tooth (1a), the second convex tooth (2a), the first groove (1b), and the second groove (2b) are rectangular, triangular, trapezoidal, or dovetail-shaped.

Images