Cut-off device for sewing machine

Abstract

This invention discloses a cutting device for a sewing machine, comprising an upper blade assembly and a lower blade assembly. The upper blade assembly includes an upper blade that can be operably moved toward the lower blade assembly to perform a cutting operation. The lower blade assembly includes: a blade holder fixed to the working arm of the sewing machine; a lower blade whose bottom is placed on the blade holder, with one end edge of the lower blade defined as the lower cutting edge, and the first end of the lower blade pivotally connected to the blade holder by a pivot shaft, and a stop portion provided at the bottom end of the lower blade; an adjusting screw that is screwed onto the blade holder, with its head positioned on the movement path of the stop portion of the lower blade; and an elastic element disposed between the lower blade and the working arm, elastically pushing the lower blade so that the stop portion of the lower blade normally rests against the head of the adjusting screw. By adjusting the position of the adjusting screw, the contact angle between the lower cutting edge of the lower blade and the upper blade of the upper blade assembly can be adjusted to meet the cutting requirements of different materials.

Description

Technical Field

[0001] This invention relates to the field of knitting equipment technology, and more particularly to a cutting device for a sewing machine. Background Technology

[0002] Currently used cutting devices in sewing machines, such as utility model patent application number 201820668180.4, include: a body with a guide cavity recessed at its front end and a through hole axially provided at the bottom end of the guide cavity; an actuating element fixed to a fixed object, the actuating element including an actuating rod connected to the body to link the movement of the body; and a cutter holder with a guide shaft protruding axially, the guide shaft fitting into the guide cavity to guide the cutter holder to move axially along the guide cavity, and the guide shaft... The end is axially recessed with a receiving cavity, and a shaft hole passes through the bottom of the receiving cavity; a spring is placed between the receiving cavity of the cutter holder and the bottom of the guide cavity of the body, and normally elastically pushes the cutter holder outward; an adjusting rod has a screw section at its rear end, which passes through the shaft hole of the cutter holder, through the through hole of the body and outward, and is screwed with at least one adjusting nut; and a blade is locked to the front end of the cutter holder, so that the body is actuated by the actuating element to drive the blade to cut the workpiece located below.

[0003] The aforementioned utility model patent application number 201820668180.4 requires a spring and an adjusting rod to adjust the spring tension in order for the blade to elastically rest against the anvil below during cutting operations. However, since all these components are mounted on an actuating rod that moves up and down, in addition to the complex structure and inconvenient installation, the adjusting rod locked on the actuating rod is very prone to loosening after the actuating rod moves up and down rapidly several times to move the blade up and down for cutting operations. This affects the accuracy of the cutting operation, and at this time, the sewing operation needs to be stopped and readjusted, so there is a clear need for improvement.

[0004] In view of this, the inventor of this case conducted further research and innovation, and finally revealed the cutting device of the sewing machine disclosed in this invention. Summary of the Invention

[0005] The present invention aims to provide a cutting device for a sewing machine, comprising an upper cutting assembly and a lower cutting assembly. The upper cutting assembly includes an upper cutting blade operably movable toward the lower cutting assembly to perform a cutting operation. The lower cutting assembly includes: a cutting block fixed to the working arm of the sewing machine; a lower cutting blade, the bottom of which rests against the cutting block, one end edge of which is defined as the lower cutting edge; a first end of the lower cutting blade pivotally connected to the cutting block by a pivot shaft; and a stop portion provided on the lower cutting blade; an adjustment... The screw includes a screw section with a head formed at one end of the screw section, the screw section being screwed onto the cutter holder, and the head being positioned on the movement path of the stop; and an elastic element that elastically pushes the lower cutter, causing the stop of the lower cutter to elastically abut against the head of the adjusting screw. By adjusting the position of the adjusting screw, the angle of contact between the lower cutter and the upper cutter is achieved, and the elastic element causes the lower cutting edge of the lower cutter to elastically press against the upper cutter during the cutting process.

[0006] The cutting device of the sewing machine disclosed in this invention further includes a limiting plate, the first end of which is locked to the blade holder, and the second end of which is radially formed with a retaining portion, such that the retaining portion abuts against the upper edge of the lower blade.

[0007] The cutting device of the sewing machine disclosed in this invention has a recessed portion at the second end of the lower blade to allow the retaining portion to extend into it.

[0008] The cutting device of the sewing machine disclosed in this invention further includes a positioning screw that is locked onto the cutter holder, such that the front end of the positioning screw is radially pressed against the adjusting screw.

[0009] The cutting device for a sewing machine disclosed in this invention includes an upper blade assembly comprising: a fixed base for locking onto a drive rod, with a guide hole passing through the fixed base; a blade holder including a fixed plate, with a guide shaft connected to the fixed plate and a guide groove provided on the guide shaft, allowing the guide shaft to slide in the shaft hole of the fixed base; a positioning screw screwed into the fixed base, with its front end extending into the guide groove; and an upper blade locked onto the fixed plate.

[0010] The cutting device of the sewing machine disclosed in this invention has a guide portion protruding downward at one end of the upper blade, such that the bottom end of the guide portion forms a guide slope towards the lower blade assembly.

[0011] The cutting device of the sewing machine disclosed in this invention has an axial hole through the end of the guide shaft, and a screw hole is formed at the front part of the shaft hole to screw in an adjusting bolt, so that the bolt head of the adjusting bolt abuts against the fixed seat, and a compression spring supports the bottom end of the adjusting bolt and the shaft hole.

[0012] The cutting device of the sewing machine disclosed in this invention includes a clamping groove on the fixed base, which is laterally passed through the guide hole, and at least one clamping bolt is locked between the two sides of the clamping groove.

[0013] The cutting device for a sewing machine disclosed in this invention ensures that, during the cutting operation, the lower blade of the lower blade is kept close to the edge of the upper blade when the upper blade slides past the lower blade. This not only ensures timely cutting but also keeps the lower blade of the lower blade sharp.

[0014] The cutting device for a sewing machine disclosed in this invention eliminates the conventional design of installing a complex retractable structure on the upper blade, and improves the disadvantage that the retractable structure may become loose or displaced due to the rapid up-and-down reciprocating motion of the upper blade, requiring recalibration. This demonstrates the novelty and progress of this invention. Attached Figure Description

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0016] Figure 1 This is a partial exploded perspective view of the present invention;

[0017] Figure 2 yes Figure 1 A schematic diagram of the assembled 3D structure;

[0018] Figure 3 yes Figure 2 A magnified view of a portion of the image;

[0019] Figure 4 This is a top partial cross-sectional view of an embodiment of the cutting device for a sewing machine provided by the invention;

[0020] Figure 5 This is a front partial cross-sectional structural schematic diagram of an embodiment of the cutting device of a sewing machine provided by the invention.

[0021] Reference numerals: 101-Working arm, 102-Drive rod, 10-Upper blade assembly, 11-Fixed seat, 111-Guide hole, 112-Pressure groove, 113-Pressure bolt, 12-Tool holder, 121-Fixed plate, 122-Guide shaft, 122a-Screw hole, 123-Guide groove, 124-Adjusting bolt, 124a-Bolt head, 13-Guide pin, 14-Upper blade, 141-Upper cutting edge, 142-Guide part, 142a - Guide slope, 20 - Lowering blade assembly, 21 - Tool holder, 22 - Lowering blade, 22a - First end, 22b - Second end, 221 - Lower cutting edge, 222 - Rotating shaft, 223 - Stop, 23 - Adjusting screw, 231 - Screw section, 232 - Head, 24 - Elastic element, 224 - Recess, 25 - Positioning screw, 251 - Front end, 26 - Rotating shaft fixing screw, 30 - Limiting plate, 31 - First end, 32 - Holding part. Detailed Implementation

[0022] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] Please see Figures 1-5 As shown, the present invention relates to a cutting device for a sewing machine, comprising an upper blade assembly 10 and a lower blade assembly 20. The upper blade assembly 10 includes an upper blade 14, which is operably movable toward the lower blade assembly 20 to perform a cutting operation. The lower blade assembly 20 includes: a blade holder 21 fixed to the working arm 101 of the sewing machine; and a lower blade 22, the bottom of which rests against the blade holder 21. One top edge of the lower blade 22 is defined as a lower cutting edge 221. The first end 22a of the lower blade 22 is pivotally connected to the blade holder 21 by a pivot 222. The lower cutter 22 is provided with a stop 223; an adjusting screw 23, including a screw section 231, with a head 232 formed at one end of the screw section 231, so that the screw section 231 is screwed onto the cutter holder 21, and the head 232 is located on the movement path of the stop 223; and an elastic element 24, which can be installed between the lower cutter 22 and the working arm 101, or between the lower cutter 22 and the fixed object. The elastic element 24 elastically pushes the lower cutter 22 under normal conditions, causing the stop 223 of the lower cutter 22 to elastically abut against the head 232 of the adjusting screw 23 and stop, i.e. Figure 4 As shown, when the adjusting screw 23 is unscrewed, the elastic element 24 will elastically push the second end 22b of the lower blade 22 to rotate along the rotating shaft 222, as... Figure 4 As shown by the dotted line, the angle A1 of contact between the lower blade 22 and the upper blade 14 can be adjusted. This invention does not limit this. The elastic element 24 keeps the lower blade 221 of the lower blade 22 close to the upper blade 14 during the cutting process, so as to smoothly cut the workpiece located between the upper blade 14 and the lower blade 22.

[0024] like Figure 1 As shown, the aforementioned rotating shaft 222 is fixed by a rotating shaft fixing screw 26 that is locked into the tool holder 21.

[0025] like Figure 1 , Figure 3 and Figure 5 As shown, the cutting device of the sewing machine disclosed in this invention has the bottom of the lower blade 22 resting flat against a fixed blade holder 21. The blade holder 21 can be locked onto the working arm 101 of the sewing machine, or is integrally formed into the working arm 101. Therefore, this invention can completely overcome the downward force on the lower blade 22 during the cutting operation, so as to avoid the lower blade 22 vibrating during the cutting process and affecting the cutting operation.

[0026] like Figure 1 , Figure 2 and Figure 3 As shown, the cutting device of the sewing machine disclosed in this invention further includes a limiting plate 30, the first end 31 of which is locked to the blade holder 21, and the second end of which is radially formed with a retaining part 32, so that the retaining part 32 abuts against the upper edge of the second end 22b of the lower blade 22 to block the reaction force generated by the second end 22b of the lower blade 22 during the cutting operation, and to prevent the second end 22b of the lower blade 22 from jumping or displacing upward, so as to ensure that the cutting operation is completed smoothly.

[0027] like Figure 1 and Figure 3 As shown, the cutting device of the sewing machine disclosed in this invention has a recessed portion 224 at the second end 22b of the lower blade 22 to allow the retaining portion 32 to extend into it.

[0028] like Figure 1 As shown, the cutting device of the sewing machine disclosed in this invention further includes a positioning screw 25 on the cutter holder 21, such that the front end 251 of the positioning screw 25 is radially pressed against the adjusting screw 23, for example, the head 232 of the adjusting screw 23, to prevent the adjusting screw 23 from loosening.

[0029] like Figure 1 , Figure 2 and Figure 3As shown, the cutting device of the sewing machine disclosed in this invention includes an upper blade assembly 10 comprising: a fixed base 11 for locking onto a drive rod 102, wherein the drive rod 102 refers to, for example, a piston rod driven by a pneumatic / hydraulic cylinder or a valve rod of a solenoid valve, or a connecting rod connected to the aforementioned piston rod or valve rod; this invention is not limited thereto; a guide hole 111 is provided through the fixed base 11; and a blade holder 12, comprising a fixed plate 121, and a guide shaft 1 is longitudinally connected to the fixed plate 121. 22, and a guide groove 123 is provided on the guide shaft 122, so that the guide shaft 122 slides in the guide hole 111 of the fixed base 11; a guide pin 13 is inserted in the fixed base 11, so that the front end of the guide pin 13 extends into the guide groove 123, so that the guide shaft 122 can stably move axially in the guide hole 111 along the direction of the guide groove 123 without rotating; and an upper blade 14 is locked on the fixed plate 121, the upper blade 14 having an upper cutting edge 141.

[0030] like Figure 1 and Figure 5 As shown, the cutting device of the sewing machine disclosed in this invention has a guide portion 142 protruding downward at one end of the upper blade 14, such that the bottom end of the guide portion 142 forms a guide slope 142a facing the lower blade assembly 20.

[0031] like Figure 1 and Figure 3 As shown, the cutting device of the sewing machine disclosed in this invention has a screw hole 122a axially passing through the end of the guide shaft 122 to screw in an adjusting bolt 124, so that the bolt head 124a of the adjusting bolt 124 abuts against the fixed seat 11. Thus, by rotating the adjusting bolt 124, the guide shaft 122 of the blade holder 12 can be axially displaced in the guide hole 111, that is, the displacement of the upper blade 14 can be adjusted axially in sync.

[0032] like Figure 1 , Figure 3 As shown, the cutting device of the sewing machine disclosed in this invention includes a clamping groove 112 provided in the fixed base 11, which is laterally passed through the guide hole 111. At least one clamping bolt 113 is locked between the two sides of the clamping groove 112 to clamp and fix the guide shaft 122 in the guide hole 111.

[0033] like Figure 5 As shown, the sewing machine cutting device disclosed in this invention has the upper blade 14 moving at an angle A2 to the vertical line, that is, moving at an inclined angle toward the lower blade 22 to perform the cutting work, that is, cutting the workpiece in an oblique manner. This invention does not limit this.

[0034] The cutting device of the sewing machine disclosed in this invention, since the lower blade 22 in the lower blade assembly 20 is normally elastically pushed by the elastic element 24, can ensure that when the upper blade 14 slides over the lower blade 22, the lower blade edge 221 of the lower blade 22 can be close to the edge of the upper blade 14. In addition to ensuring the timely cutting operation, it can also keep the lower blade edge 221 of the lower blade 22 sharp.

[0035] The cutting device for a sewing machine disclosed in this invention eliminates the conventional design of installing a complex retractable structure on the upper blade, and improves the disadvantage that the retractable structure may become loose or displaced due to the rapid up-and-down reciprocating motion of the upper blade, requiring recalibration. This demonstrates the novelty and progress of this invention.

[0036] The structures and shapes disclosed in this invention may be modified without departing from the spirit and scope of this invention, and this invention is not limited to the above-described embodiments.

[0037] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0038] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A cutting device of a sewing machine, characterized by, include: An upper cutting assembly and a lower cutting assembly, wherein the upper cutting assembly includes an upper cutting blade that is operable to move toward the lower cutting assembly to perform a cutting operation; The cutting assembly includes: A cutter holder, fixed to the working arm of the sewing machine; The bottom of the lower blade rests flat against the blade holder. The top edge of one side of the lower blade is defined as the lower cutting edge. The first end of the lower blade is pivotally connected to the blade holder by a pivot, and a stop is provided on the lower blade. An adjusting screw includes a screw section with a head formed at one end of the screw section, such that the screw section is screwed onto the tool holder, and the head is positioned on the movement path of the stop; and An elastic element is installed between the lower cutter and a fixed object. Normally, the elastic element elastically pushes the lower cutter, causing the stop of the lower cutter to elastically abut against the head of the adjusting screw and then stop. The upper blade assembly system includes: A fixed base for locking onto a drive rod, and a guide hole is provided through the fixed base; A tool holder includes a fixed plate and a guide shaft is longitudinally connected to the fixed plate. A guide groove is provided on the guide shaft so that the guide shaft slides in the guide hole of the fixed seat. A screw hole is axially provided at the end of the guide shaft so as to screw an adjusting bolt so that the bolt head of the adjusting bolt abuts against the fixed seat. A guide pin is inserted into the fixed seat, with its front end extending into the guide groove, allowing the guide shaft to stably move axially within the guide hole along the direction of the guide groove without rotation; and An upper blade is locked to the fixing plate, and the upper blade contains an upper cutting edge.

2. The cutting device for a sewing machine according to claim 1, characterized in that, It further includes a limiting plate, the first end of which is locked to the tool holder, and the second end of which is radially formed with a retaining portion, such that the retaining portion abuts against the upper edge of the second end of the lower tool.

3. The cutting device for a sewing machine according to claim 2, characterized in that, The second end of the cutting tool is recessed to allow the retaining part to extend inside.

4. The cutting device for a sewing machine according to claim 1, characterized in that, The tool holder is further secured with a positioning screw, so that the front end of the positioning screw radially presses against the adjusting screw.

5. The cutting device for a sewing machine according to claim 1, characterized in that, The upper blade has a guide portion protruding downward at one end, with the bottom end of the guide portion forming a guide slope facing the lower blade assembly.

6. The cutting device for a sewing machine according to claim 1, characterized in that, The mounting base is provided with a clamping groove, which passes through the guide hole laterally. At least one clamping bolt is locked between the two sides of the clamping groove to clamp and fix the guide shaft in the guide hole.

7. The cutting device for a sewing machine according to claim 1, characterized in that, The movement path of the upper blade is at a preset angle to the vertical line.

8. The cutting device for a sewing machine according to claim 1, characterized in that, The shaft is secured by a shaft fixing screw that locks into the tool holder.

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