Longitudinal welding production equipment and process for nerve operation pad

Abstract

The invention relates to a split type nerve operation pad production mold, and aims to solve the problems of quick abrasion, low replacement efficiency and resource waste caused by frequent compression in the nerve operation pad production process of an existing integral mold. The mold comprises a mold fixing seat, a mold base and a pressing piece arranged on the top face of the mold base. A cotton piece groove is formed in the middle of the die base, pressing pieces fixed through connecting bolts are installed on the two sides of the die base respectively, and barium wire guide grooves and strip holes are formed in the pressing pieces. And a gap for the cotton piece to pass through is formed between the pressing strip, extending to the upper part of the two sides of the cotton piece groove, on one side of the pressing piece and the cotton piece groove. The modular design adopted in the invention allows quick replacement of worn parts, and the whole mold does not need to be disassembled, so that the production efficiency is remarkably improved, the maintenance cost is reduced, and the resource waste is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical product processing, and specifically to a longitudinal welding production device and process for a nerve surgery pad. Background Art

[0002] As an important medical consumable, a nerve surgery pad is widely used in surgical operations to provide a sterile barrier and achieve intraoperative imaging and positioning. Among them, barium wires, as imaging marking wires, need to be combined with a non-woven fabric substrate through a welding process. In traditional production processes, barium wires usually adopt a transverse welding method, that is, the barium wires are arranged along the width direction of the non-woven fabric and fixed by welding. However, this process has significant defects: since the non-woven fabric needs to bear longitudinal tension during the transmission process on the production line, the welding points of the barium wires formed by transverse welding will concentrate local stress. Especially in the application scenario of thin non-woven fabrics (such as those with a grammage lower than 30 g / m²), the welding area is extremely prone to substrate tearing or barium wire detachment due to stretching. This not only affects the integrity of the product structure but also may cause intraoperative positioning deviation due to the breakage of the imaging wire, posing a medical risk. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a longitudinal welding production device and process for a nerve surgery pad, which can achieve the purposes of precise longitudinal welding of barium wires, dynamic tension control, and efficient slitting, so as to improve the mechanical properties and process stability of the nerve surgery pad.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a longitudinal welding production device for a nerve surgery pad, including a raw material feeding rack, a welding table, and a cutting table arranged in sequence along the production line direction. The raw material feeding rack is provided with a non-woven fabric roll and a barium wire roll. Along the production line direction on the welding table, there are sequentially arranged a barium wire welding mechanism and a barium wire re-welding mechanism. The raw materials released from the non-woven fabric roll and the barium wire roll extend along the production line direction and pass through the barium wire welding mechanism and the barium wire re-welding mechanism in sequence.

[0005] In a preferred solution, there are two upper and lower raw material support rods on the raw material feeding rack. A plurality of barium wire rolls are sleeved on the upper raw material support rod, and a non-woven fabric roll is sleeved on the lower raw material support rod.

[0006] In a preferred solution, there is a buffer groove between the welding table and the cutting table. On the top surface of the cutting table, a deviation rectifier is provided on one side close to the buffer groove, and a slitting mechanism is provided on the other side. The product output from the barium wire re-welding mechanism passes around the buffer groove and then passes through the deviation rectifier and the slitting mechanism in sequence.

[0007] In a preferred solution, a traction mechanism is provided on the output end direction of the top surface of the welding table. The traction mechanism consists of two upper and lower pinch rollers, and one of the pinch rollers is driven by a driving motor. The non-woven fabric passes between the two pinch rollers.

[0008] In a preferred embodiment, the slitting mechanism includes a transverse cutting mechanism and a longitudinal cutting mechanism.

[0009] In a preferred embodiment, a feeding mechanism and a plurality of barium wire guide wheels are provided in the direction of the input end of the top surface of the welding table. The main body of the feeding mechanism is a cross bar. The non-woven fabric extending from the non-woven fabric roll passes under the cross bar, and the barium wire extending from the barium wire roll bypasses above the cross bar for guiding. The barium wire extending from the barium wire roll is divided and guided through a plurality of barium wire guide wheels after passing through the feeding mechanism.

[0010] In a preferred embodiment, a barium wire deviation correction mechanism is further provided on the welding table. The barium wire output after being divided and guided by the barium wire guide wheel passes through the barium wire deviation correction mechanism to achieve the horizontal positioning of the barium wire.

[0011] In a preferred embodiment, the barium wire welding mechanism includes a welding cylinder fixed on a bracket. The push rod of the welding cylinder faces downward, and an ultrasonic welding module is provided at the end of the push rod. A non-woven fabric guide seat is provided on the welding table below the ultrasonic welding module. The non-woven fabric is arranged through the non-woven fabric guide seat. An opening larger than the ultrasonic welding module is provided on the top surface of the non-woven fabric guide seat. The ultrasonic welding module is arranged vertically aligned with the opening. A fixed jaw pushing cylinder is provided on one side of the welding cylinder close to the raw material input direction. The push rod of the fixed jaw pushing cylinder faces downward, and a fixed jaw is provided at the end of the push rod. A longitudinal track along the production line direction is provided on the welding table on one side of the barium wire welding mechanism. A movable jaw seat is provided on the longitudinal track. The movable jaw seat can move across the ultrasonic welding module along the production line direction on the longitudinal track. A longitudinal track is provided on the movable jaw seat, which is perpendicular to the production line direction. A movable jaw is provided on the longitudinal track.

[0012] In a preferred embodiment, a barium wire cutter is provided on each side of the ultrasonic welding module. The two barium wire cutters are respectively driven by separate cylinders. A negative pressure pipe for recovering the barium wire segment is further provided on one side of the barium wire cutter close to the output direction.

[0013] Based on the above production process of a longitudinal welding production device for a nerve surgery pad, it includes the following steps: S1. Unwinding of raw materials The non-woven fabric substrate and the barium wire are synchronously released from the non-woven fabric roll and the barium wire roll respectively, so that the barium wire is arranged on the surface of the non-woven fabric along the production line direction. S2. Barium wire positioning The multi-strand barium wire is divided and guided by the barium wire guide wheels, and precise horizontal positioning is achieved through the barium wire deviation correction mechanism. S3. Initial welding of barium wire The longitudinal continuous welding of the barium wire after positioning is carried out by using an ultrasonic welding module, and the barium wires on both sides of the welding point are cut off by a barium wire cutter; S4. Secondary welding of barium wire Perform secondary ultrasonic welding on the barium wire after primary welding to eliminate the curling points at both ends of the barium wire; S5. Dynamic buffering The product after secondary welding winds through the buffer groove to form a dynamic material storage section; S6. Deviation correction and slitting After correcting the position of the material tape by a deviation corrector, a slitting mechanism is used to perform transverse cutting and longitudinal slitting; The specific steps in the step S3 include the following steps: S3.1. The movable jaw clamps the end of the barium wire and drives the movable jaw seat to move along the production line direction by relying on a drag chain, so that the movable jaw clamping the barium wire is arranged right below the ultrasonic welding module; S3.2. The fixed jaw push cylinder is pushed out and the barium wire is clamped by the fixed jaw; S3.3. The ultrasonic welding module moves down and presses the barium wire onto the non-woven fabric for welding; S3.4. The barium wire cutter moves down to cut off the barium wire; S3.5. The ultrasonic welding module and the barium wire cutter move up and reset; S3.6. The movable jaw is loosened, and the negative pressure tube is used to suck and recover the wire heads generated by cutting the barium wire under negative pressure; S3.7. After the movable jaw moves laterally along the transverse track to the outside of the welding table, the drag chain drives the movable jaw seat to move along the production line direction, so that the movable jaw moves to one side of the barium wire tightened by the fixed jaw; S3.8. The movable jaw moves laterally along the transverse track towards the barium wire and clamps the barium wire, and then the fixed jaw is loosened; S3.9. Repeat steps S3.1 to S3.8.

[0014] A split-type production mold for a neurosurgical pad provided by the present invention has the following beneficial effects by adopting the above structure: (1) By welding the barium wire along the production line direction, the barium wire and the non-woven fabric are in the same tension direction, avoiding the stress concentration problem caused by transverse welding. The barium wire secondary welding mechanism performs secondary reinforcement on both ends of the welding point, further eliminating the micro-curling generated at the ends of the barium wire due to cutting, ensuring uniform stress distribution in the welding area, reducing the risk of tearing of the thin non-woven fabric under tension, and improving the tensile strength of the product; (2) The barium wire guide pulley cooperates with the barium wire deviation correction mechanism to achieve independent wire guiding and horizontal fine adjustment of multiple barium wires. The positioning accuracy can reach ±0.2 mm, avoiding welding defects caused by multi-wire crossing or deviation. The buffer tank adopts a dynamic material storage design to absorb the tension fluctuation between the welding and slitting processes, and cooperates with the deviation corrector to real-time correct the position of the material tape, ensuring that the cutting error of the slitting mechanism is less than 0.5 mm, and significantly improving the consistency of the finished product size; (3) The ultrasonic welding module and the barium wire cutter are designed in a linkage manner to complete welding and cutting synchronously. The single welding cycle is shortened to within 3 seconds. The negative pressure pipe immediately adsorbs and recovers the barium wire head after cutting, avoiding the residual wire head from contaminating the surface of the non-woven fabric, and the cleanliness meets the medical grade standard. Brief Description of the Drawings

[0015] The present invention will be further described below in conjunction with the drawings and embodiments: Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 It is a schematic three-dimensional structure diagram of the present invention.

[0017] Figures 3 - 6 It is a schematic diagram of the structure during the initial welding of the barium wire of the present invention.

[0018] Figure 7 It is a schematic diagram of the fixed jaw structure of the present invention.

[0019] Figure 8 It is a schematic diagram of the movable jaw structure of the present invention.

[0020] In the figure: raw material feeding rack 1, welding table 2, cutting table 3, raw material support rod 4, non-woven fabric roll 5, barium wire roll 6, barium wire welding mechanism 7, barium wire re-welding mechanism 8, buffer tank 9, deviation corrector 10, slitting mechanism 11, traction mechanism 12, material guiding mechanism 13, barium wire guide pulley 14, barium wire deviation correction mechanism 15, welding cylinder 16, re-welding cylinder 17, longitudinal track 18, drag chain 19, movable jaw seat 20, transverse track 21, ultrasonic welding module 22, barium wire cutter 23, non-woven fabric guide seat 24, opening 25, movable jaw 26, negative pressure pipe 27, fixed jaw 28, fixed jaw push cylinder 29. Detailed Embodiments

[0021] Embodiment 1: As Figures 1 - 2Among them, a production device for longitudinally welding a nerve surgery pad includes a raw material feeding rack 1, a welding table 2, and a cutting table 3 arranged in sequence along the production line direction. A non-woven fabric roll 5 and a barium wire roll 6 are provided on the raw material feeding rack 1. Along the production line direction on the welding table 2, a barium wire welding mechanism 7 and a barium wire re-welding mechanism 8 are successively provided. The raw materials released from the non-woven fabric roll 5 and the barium wire roll 6 extend along the production line direction and pass through the barium wire welding mechanism 7 and the barium wire re-welding mechanism 8 in sequence.

[0022] In a preferred solution, two raw material support rods 4 are provided on the raw material feeding rack 1. A plurality of barium wire rolls 6 are sleeved on the upper raw material support rod 4, and a non-woven fabric roll 5 is sleeved on the lower raw material support rod 4.

[0023] In a preferred solution, a buffer groove 9 is provided between the welding table 2 and the cutting table 3. A deviation rectifier 10 is provided on one side of the top surface of the cutting table 3 close to the buffer groove 9, and a slitting mechanism 11 is provided on the other side. The product output from the barium wire re-welding mechanism 8 passes around the buffer groove 9 and then passes through the deviation rectifier 10 and the slitting mechanism 11 in sequence.

[0024] Among them, the deviation rectifier 10 combines a CCD vision sensor and an electric sliding table to monitor the position of the barium wire in real time and perform horizontal deviation correction.

[0025] In a preferred solution, a traction mechanism 12 is provided in the output end direction of the top surface of the welding table 2. The traction mechanism 12 consists of two upper and lower pinch rollers. One of the pinch rollers is driven by a driving motor, and the non-woven fabric passes between the two pinch rollers.

[0026] The upper and lower pinch rollers of the traction mechanism 12 are driven by a servo motor, with a linear speed of 0.8 m / min and an adjustable clamping force.

[0027] In a preferred solution, the slitting mechanism 11 includes a transverse cutting mechanism and a longitudinal cutting mechanism.

[0028] The transverse cutting is carried out by a circular blade (φ150 mm) at an interval of 300 mm to cut off and form a single-piece surgery pad.

[0029] The longitudinal cutting is carried out by a laser cutting head (power 50 W) along the outside of the barium wire for trimming, with a trimming width of 2 mm.

[0030] In a preferred solution, a guiding mechanism 13 and a plurality of barium wire guide wheels 14 are provided in the input end direction of the top surface of the welding table 2. The main body of the guiding mechanism 13 is a cross bar. The non-woven fabric extended from the non-woven fabric roll 5 passes under the cross bar, and the barium wire extended from the barium wire roll 6 bypasses above the cross bar for guiding; The barium wire extended from the barium wire roll 6 is divided and guided through a plurality of barium wire guide wheels 14 after passing around the guiding mechanism 13.

[0031] In a preferred solution, a barium wire alignment mechanism 15 is further provided on the welding table 2. The barium wire output after being branched and guided by the barium wire guide pulley 14 passes through the barium wire alignment mechanism 15 to achieve the horizontal positioning of the barium wire.

[0032] In a preferred solution, the barium wire welding mechanism 7 includes a welding cylinder 16 fixed on the bracket. The push rod of the welding cylinder 16 faces downward, and an ultrasonic welding module 22 is provided at the end of the push rod. A non-woven fabric guide seat 24 is provided on the welding table 2 below the ultrasonic welding module 22. The non-woven fabric is arranged through the non-woven fabric guide seat 24. An opening 25 larger than the ultrasonic welding module 22 is provided on the top surface of the non-woven fabric guide seat 24. The ultrasonic welding module 22 is arranged vertically aligned with the opening 25; On one side of the welding cylinder 16 close to the raw material input direction, a fixed jaw pushing cylinder 29 is provided. The push rod of the fixed jaw pushing cylinder 29 faces downward, and a fixed jaw 28 is provided at the end of the push rod; On the welding table 2 on one side of the barium wire welding mechanism 7, a longitudinal track 18 along the production line direction is provided. A movable jaw seat 20 is provided on the longitudinal track 18. The movable jaw seat 20 can move across the ultrasonic welding module 22 along the production line direction on the longitudinal track 18. A longitudinal track 18 is provided on the movable jaw seat 20. The longitudinal track 18 is arranged perpendicular to the production line direction. A movable jaw 26 is provided on the longitudinal track 18.

[0033] In a preferred solution, a barium wire cutter 23 is provided on each side of the ultrasonic welding module 22. The two barium wire cutters 23 are respectively driven by separate cylinders. A negative pressure pipe 27 for recovering the barium wire segments is further provided on one side of the barium wire cutter 23 close to the output direction.

[0034] Embodiment 2: Based on the production process of a longitudinal welding production device for a nerve surgery pad described in Embodiment 1, the following steps are included: S1. Raw material unwinding The non-woven fabric substrate and the barium wire are respectively unwound from the non-woven fabric roll and the barium wire roll synchronously, so that the barium wire is arranged on the surface of the non-woven fabric along the production line direction; S2. Barium wire positioning The barium wire guide pulley is used to branch and guide multiple barium wires, and precise horizontal positioning is achieved through the barium wire alignment mechanism; S3. Primary barium wire welding The ultrasonic welding module is used to longitudinally and continuously weld the positioned barium wire, and the barium wire on both sides of the welding point is cut off by the barium wire cutter; S4. Secondary barium wire welding The primary welded barium wire is subjected to secondary ultrasonic welding to eliminate the curled points at both ends of the barium wire; S5. Dynamic buffering The product after secondary welding winds through the buffer groove to form a dynamic storage section; S6. Deviation correction and slitting After correcting the position of the material tape by the deviation corrector, the transverse cutting and longitudinal slitting are carried out by the slitting mechanism; The specific steps in the step S3 include the following steps: S3.1. The movable jaw clamps the end of the barium wire, and the movable jaw seat is driven by the drag chain to move along the production line direction, so that the movable jaw clamping the barium wire is arranged directly below the ultrasonic welding module; S3.2. The fixed jaw push cylinder is pushed out and the barium wire is clamped by the fixed jaw; S3.3. The ultrasonic welding module moves down and presses the barium wire onto the non-woven fabric for welding; S3.4. The barium wire cutter moves down to cut the barium wire; S3.5. The ultrasonic welding module and the barium wire cutter move up and reset; S3.6. The movable jaw is loosened, and the negative pressure tube is used to suck and recover the wire head generated by cutting the barium wire under negative pressure; S3.7. After the movable jaw moves laterally along the transverse track to the outside of the welding table, the drag chain drives the movable jaw seat to move along the production line direction, so that the movable jaw moves to one side of the barium wire tightened by the fixed jaw; S3.8. After the movable jaw moves laterally along the transverse track towards the barium wire and clamps the barium wire, the fixed jaw is loosened; S3.9. Repeat steps S3.1 to S3.8.

[0035] Example 3: To produce a nerve surgery pad with 3 parallel barium wires, the equipment is adjusted as follows: Three barium wire reels 6 are installed on the upper layer of the raw material feeding rack 1, the number of barium wire guide wheels 14 is increased to 3 groups, and the wire separation distance is adjusted to 80 mm.

[0036] The longitudinal cutting heads of the slitting mechanism 11 are set to 3 groups, corresponding to the positions 2 mm outside the barium wires respectively.

[0037] The other process parameters are the same as those in Example 1. The final product has a barium wire spacing of 80 mm and a parallelism error of the developing wire ≤ 0.3 mm.

Claims

1. A longitudinal welding production device for a nerve surgery pad, characterized in that: It includes a raw material feeding rack (1), a welding table (2) and a cutting table (3) arranged in sequence along the production line direction. A non-woven fabric roll (5) and a barium wire roll (6) are provided on the raw material feeding rack (1). Along the production line direction on the welding table (2), a barium wire welding mechanism (7) and a barium wire re-welding mechanism (8) are provided in sequence. The raw materials released from the non-woven fabric roll (5) and the barium wire roll (6) extend along the production line direction and sequentially pass through the barium wire welding mechanism (7) and the barium wire re-welding mechanism (8).

2. The longitudinal welding production equipment for a nerve surgery pad according to claim 1, characterized in that: On the raw material feeding rack (1), there are two upper and lower raw material support rods (4). A plurality of barium wire rolls (6) are sleeved on the upper raw material support rod (4), and a non-woven fabric roll (5) is sleeved on the lower raw material support rod (4).

3. A longitudinal welding production device for a nerve surgery pad according to claim 1, characterized in that: A buffer groove (9) is provided between the welding table (2) and the cutting table (3). On one side of the top surface of the cutting table (3) close to the buffer groove (9), a deviation rectifier (10) is provided, and on the other side, a slitting mechanism (11) is provided. The product output from the barium wire re-welding mechanism (8) passes around the buffer groove (9) and then sequentially passes through the deviation rectifier (10) and the slitting mechanism (11).

4. A longitudinal welding production device for a nerve operation pad according to claim 1, characterized in that: On the output end direction of the top surface of the welding table (2), a traction mechanism (12) is provided. The traction mechanism (12) consists of two upper and lower pinch rollers. One of the pinch rollers is driven by a driving motor, and the non-woven fabric passes through between the two pinch rollers.

5. A longitudinal welding production device for a nerve surgery pad according to claim 3, characterized in that: The slitting mechanism (11) includes a transverse cutting mechanism and a longitudinal cutting mechanism.

6. The longitudinal welding production equipment for a nerve surgery pad according to claim 1, characterized in that: On the input end direction of the top surface of the welding table (2), a guiding mechanism (13) and a plurality of barium wire guide wheels (14) are provided. The main body of the guiding mechanism (13) is a cross bar. The non-woven fabric extending from the non-woven fabric roll (5) passes under the cross bar, and the barium wire extending from the barium wire roll (6) bypasses above the cross bar to achieve guiding; The barium wire extending from the barium wire roll (6) passes around the guiding mechanism (13) and is divided and guided by a plurality of barium wire guide wheels (14).

7. A longitudinal welding production device for a nerve surgery pad according to claim 6, characterized in that: A barium wire deviation rectifying mechanism (15) is also provided on the welding table (2). The barium wire output after being divided and guided by the barium wire guide wheels (14) passes through the barium wire deviation rectifying mechanism (15) to achieve the positioning of the barium wire in the horizontal direction.

8. A longitudinal welding production device for a nerve surgery pad according to claim 1, characterized in that: The barium wire welding mechanism (7) includes a welding cylinder (16) fixed on a bracket. The push rod of the welding cylinder (16) faces downward, and an ultrasonic welding module (22) is provided at the end of the push rod. On the welding table (2) below the ultrasonic welding module (22), a non-woven fabric guide seat (24) is provided. The non-woven fabric passes through the non-woven fabric guide seat (24). An opening (25) with a size larger than the ultrasonic welding module (22) is provided on the top surface of the non-woven fabric guide seat (24). The ultrasonic welding module (22) is arranged vertically aligned with the opening (25); On one side of the welding cylinder (16) close to the raw material input direction, a fixed jaw pushing cylinder (29) is provided. The push rod of the fixed jaw pushing cylinder (29) faces downward, and a fixed jaw (28) is provided at the end of the push rod; On the welding table (2) on one side of the barium wire welding mechanism (7), there is a longitudinal track (18) along the production line direction. An active jaw seat (20) is arranged on the longitudinal track (18), and the active jaw seat (20) can move across the ultrasonic welding module (22) along the production line direction on the longitudinal track (18). There is a longitudinal track (18) on the active jaw seat (20), and the longitudinal track (18) is arranged perpendicular to the production line direction. An active jaw (26) is arranged on the longitudinal track (18).

9. The longitudinal welding production equipment for a nerve surgery pad according to claim 8, characterized in that: On both sides of the ultrasonic welding module (22), there is a barium wire cutter (23) respectively. The two barium wire cutters (23) are respectively driven by separate cylinders. On the side of the barium wire cutter (23) close to the output direction, there is also a negative pressure pipe (27) for recovering barium wire segments.

10. The production process of a longitudinal welding production device for a nerve surgery pad according to any one of claims 1-9, characterized in that Including the following steps: S1. Unwinding of raw materials The non-woven fabric substrate and the barium wire are respectively unwound from the non-woven fabric roll (5) and the barium wire roll (6) synchronously, so that the barium wire is arranged on the surface of the non-woven fabric along the production line direction. S2. Barium wire positioning The multi-strand barium wire is split and guided by the barium wire guide wheel (14), and horizontal precise positioning is achieved through the barium wire deviation rectifying mechanism (15). S3. Primary welding of barium wire The positioned barium wire is longitudinally continuously welded by the ultrasonic welding module (22), and the barium wire on both sides of the welding point is cut off by the barium wire cutter (23). S4. Secondary welding of barium wire The barium wire after primary welding is subjected to secondary ultrasonic welding to eliminate the curled points at both ends of the barium wire. S5. Dynamic buffering The product after secondary welding passes through the buffer tank (9) to form a dynamic storage section. S6. Deviation rectifying and slitting After the position of the strip is corrected by the deviation rectifier (10), the transverse cutting and longitudinal slitting are carried out by the slitting mechanism (11). The specific steps in the step S3 include the following steps: S3.

1. The active jaw (26) clamps the end of the barium wire and drives the active jaw seat (20) to move along the production line direction by relying on the drag chain (19), so that the active jaw (26) clamping the barium wire is arranged directly below the ultrasonic welding module (22). S3.

2. The fixed jaw push cylinder (29) pushes out and clamps the barium wire through the fixed jaw (28). S3.

3. The ultrasonic welding module (22) moves down and presses the barium wire onto the non-woven fabric for welding. S3.

4. The barium wire cutter (23) moves down to cut off the barium wire. S3.

5. The ultrasonic welding module (22) and the barium wire cutter (23) move up and reset. S3.

6. The active jaw (26) loosens, and cooperates with the negative pressure pipe (27) to carry out negative pressure adsorption and recovery of the wire heads generated by cutting the barium wire. S3.

7. After the active jaw (26) moves along the transverse track (21) to the outside of the welding table (2), the drag chain (19) drives the active jaw seat (20) to move along the production line direction, so that the active jaw (26) moves to one side of the barium wire tightened by the fixed jaw (28). S3.

8. After the active jaw (26) moves along the transverse track (21) towards the barium wire and clamps the barium wire, the fixed jaw (28) loosens. S3.

9. Repeat steps S3.1 to S3.8.

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