EP2570531B1

EP2570531B1 - Downward pressing mesh mechanism and sinker thereof for flat knitting machines

Info

Publication number: EP2570531B1
Application number: EP20110181406
Authority: EP
Inventors: Yi Chen Chen; Kai Ying Cheng; Jian-Hao Peng
Original assignee: Pai Lung Machinery Mill Co Ltd
Current assignee: Pai Lung Machinery Mill Co Ltd
Priority date: 2011-09-15
Filing date: 2011-09-15
Publication date: 2014-03-05
Anticipated expiration: 2031-09-15
Also published as: EP2570531A1

Description

FIELD OF THE INVENTION

The present invention relates to a downward pressing mechanism for a flat knitting machine to press a yarn to form a knitted fabric and to a sinker thereof.

BACKGROUND OF THE INVENTION

When a protrusive pattern cloth (i.e. jacquard fabric) is knitted via a conventional flat knitting machine, sinkers are swung about a shaft to press a yarn downwards to form a knitted fabric to knit the protrusive pattern cloth.
For instance, Taiwanese patent No. 338440 entitled "Improved sinker for flat knitting machines" discloses a sinker 10 that is braced by a bracing rod 22 to achieve swinging. When a flat knitting machine is in production and assembly, a bracing rod 22 needs to run through all the sinkers 10 individually for coupling. Moreover, during repair and maintenance, the sinkers 10 also have to be removed individually for replacement as needed, and then reassembled individually again. This is troublesome, tedious and time-consuming.
Taiwanese patent No. 1274796 entitled "Sinker for flat knitting machines to downward press mesh" discloses a sinker 1 with a slot 19 threaded through by a loosening yarn 45 of the knitted fabric as shown in its FIG. 1. The loosening yarn 45 of the knitted fabric has to be threaded individually through all the sinkers 1 and also has to be removed individually therefrom to replace the broken one during repair and maintenance. After a new sinker I has been replaced, the loosening yarn 45 of the knitted fabric has to be thread through all the sinkers 1 again. The process also is troublesome and time-consuming.
In short, while the aforesaid conventional techniques provide a retaining shaft swinging function, they still have drawbacks, notably:

1. During production and assembly of the downward pressing mechanism in the conventional flat knitting machine, assembly of the sinkers is troublesome and time-consuming.
2. During repair and maintenance of the downward pressing mechanism in the conventional flat knitting machine, replacement of the sinkers also is difficult and tedious.
3. Due to assembly of the sinkers of the downward pressing mechanism in the conventional flat knitting machine is troublesome and time-consuming, labor cost is higher to result in higher product price, thus cannot meet market requirements.

WO 95/07382 A discloses a device for holding down the stitches being formed in a flat knitting machine. The device includes at least one needle bed having a plurality of needles and pressing means located between two plates, which is controlled by a flat cam fastened to the carriage of the machine. The plate has a hole, through which a stem passes. The pressing means includes a head, a butt extending from each one of the pressing means, and a recess through which a supporting rod extends. The sinker is designed based on a substantially different approach according to which the sinkers are simply hanged or hinged onto the associated bracing shaft. A shaft coupling portion in the sense of the present invention is not disclosed. In particular the sinker neither has an elastic tongue nor a groove enabling the elastic movement of the elastic tongue.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve the aforesaid disadvantages and to provide a simpler and more durable sinker for a flat knitting machine and a corresponding downward pressing mechanism.
This problem is solved by a sinker according to claim 1 and by a downward pressing mechanism according to claim 4. Further advantageous embodiments are the subject-matter of the dependent claims.
A sinker according to the present invention can be produced and assembled or repaired, maintained and replaced more easily and quickly to thus reduce manpower and material costs and also lower price to meet market requirements.
A downward pressing mechanism for a flat knitting machine according to the present invention comprises a needle seat including a bearing surface to hold a plurality of sinkers and knitting needles separated by spacers, and a cam holder located above the sinkers to hold a cam. The cam has a guide track to drive the sinker swinging. A bracing shaft extends perpendicularly through the spacers at a lower side thereof. Each sinker comprises a yarn pressing portion to press a yarn to form a knitted fabric, a swing guide portion driven by the guide track, and a shaft rotating recess to couple with the bracing shaft.
According to the present invention the shaft rotating recess comprises a shaft coupling portion to couple with the bracing shaft and a neck located at an entrance of the shaft coupling portion that is formed at an interval smaller than the diameter of the bracing shaft.
A retaining rod extends perpendicularly through the spacers at an upper side thereof, and the sinker includes a first retaining portion restricted by the bearing surface when the sinker rotates and swings downwards and a second retaining portion restricted by the retaining rod when the sinker rotates and swings upwards.
According to a further embodiment a guiding rod extends perpendicularly through the spacers and the sinker has a guiding notch with a guiding surface formed thereon to guide and limit rotating and swinging positions of the sinker.
According to the present invention each sinker further comprises a groove close to the shaft rotating recess and an elastic tongue formed between the groove and the shaft rotating recess.
A sinker of the present invention comprises a shaft rotating recess disposed at the bottom of the sinker, a swing guide portion extended outwards from an upper side of the sinker, and a yarn pressing portion protruded from one side of the sinker beyond a line connecting the swing guide portion and the shaft rotating recess to press a yarn to form a knitted fabric. The shaft rotating recess comprises a shaft coupling portion configured to couple with a bracing shaft. According to the present invention the sinker further comprises a groove close to the shaft rotating recess and an elastic tongue formed between the groove and the shaft rotating recess, wherein a neck located at an entrance of the shaft coupling portion is formed at an interval slightly smaller than the maximum interval of the shaft coupling portion.
According to a further embodiment the sinker has a first retaining portion between the shaft rotating recess and yarn pressing portion.
According to a further embodiment the sinker has a guiding notch at another side beyond a line connecting the swing guide portion and shaft rotating recess that has an arched guiding surface at a lower side, and a second retaining portion located between the guiding notch and swing guide portion.
By means of the features set forth above the present invention provides many advantages over the conventional techniques, notably:

1. During production and assembly of the downward pressing mechanism, the sinkers can be assembled in the downward pressing mechanism by direct insertion. Thus this process is easier and faster.
2. During repair and maintenance of the downward pressing mechanism, the old sinker can be directly removed in the downward pressing mechanism and replaced by a new one. Thus this process also is easier and faster.
3. Since the sinkers can be assembled easier and faster, labor cost is lower and product price also can be reduced to meet market requirements.
4. The sinker of the invention can be integrally formed. Hence design and structure are simpler and more durable, and material cost can also be reduced to lower the product price to meet market requirements.

The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plane view of an embodiment of the invention before assembly.
FIG. 2 is a schematic view according to FIG. 1 in an assembly condition.
FIG. 3 is a schematic view according to FIG. 2 in another assembly condition.
FIG. 4 is an enlarged plane view of an embodiment of a sinker of the invention.
FIG. 5 is a schematic view of the sinker of an embodiment of the invention in a use condition.
FIG. 6 is a schematic view of another use condition according to FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1, 2 and 3 show a downward pressing mechanism for flat a knitting machine according to the present invention. The downward pressing mechanism 1 includes a needle seat 10 which has a bearing surface 11 to hold a plurality of sinkers 7 and knitting needles 8 separated by spacers 3. As also known in the conventional techniques, the sinkers 7, spacers 3 and knitting needles 8 are arranged sequentially and horizontally above the bearing surface 11 in a juxtaposed manner with a specific number required, and each knitting needle 8 is movable within a space formed by two sinkers 7, and the sinkers 7 also are movable in the separated space. There is a cam holder 2 above the sinkers 7 to hold a cam 20. The cam 20 has a guide track 21 to drive the sinkers 7 swinging. The guide track 21 is not formed in a straight line but at a curve depending on the requirement of knitting fabrics, thereby to drive the sinkers 7 swinging. This is also a technique known in the art. A bracing shaft 4 extends perpendicularly through the spacers 3 at the lower side thereof. Each sinker 7 includes a yarn pressing portion 75 to press a yarn to form a knitted fabric, a swing guide portion 70 driven by the guide track 21 that is preferably formed in a curved shape, and a shaft rotating recess 73 to couple with the bracing shaft 4. The yarn pressing portion 75 is protruded from one side beyond a line connecting the swing guide portion 70 and shaft rotating recess 73 and corresponds to a yarn hooking portion of the knitting needle 8 to press the yarn to form the knitted fabric. The shaft rotating recess 73 includes a shaft coupling portion 732 to couple with the bracing shaft 4 and a neck 731 located at an entrance of the shaft coupling portion 732 that is formed at an interval slightly smaller than the diameter of the bracing shaft 4. A retaining rod 5 extends perpendicularly through the spacers 3 at an upper side thereof. The sinker 7 further has a first retaining portion 71 restricted by the bearing surface 11 during rotating and swinging downward, and a second retaining portion 72 restricted by the retaining rod 5 during rotating and swinging upward. Furthermore a guiding rod 6 extends perpendicularly through the spacers 3. The sinker 7 further has a guiding notch 74 which has a guiding surface 741 to guide and limit rotating and swinging positions of the sinker 7. The guiding surface 741 is preferably an arched surface. Finally, the sinker 7 also has a groove 76 close to the shaft rotating recess 73 and an elastic tongue 77 between the groove 76 and the shaft rotating recess 73. As shown in FIGS, 1, 2 and 3, during production, assembly or repairs and maintenance, the sinker 7 can be easily and quickly assembled or changed to reduce manpower and material costs, and also reduce the price to meet market requirements.
A sinker for a flat knitting machine according to the present invention is shown in Fig. 4. The sinker 7 has a shaft rotating recess 73 at the bottom, a curved swing guide portion 70 extended from the upper side, and a yarn pressing portion 75 protruded from one side beyond a line connecting the swing guide portion 70 and shaft rotating recess 73 to press a yarn to form a knitted fabric. The shaft rotating recess 73 includes a shaft coupling portion 732 and a neck 731 at the entrance of the shaft coupling portion 732 and formed at an interval slightly smaller than the maximum interval of the shaft coupling portion 732. There is a first retaining portion 71 located between the shaft rotating recess 73 and yarn pressing portion 75. The sinker 7 also has a guiding notch 74 at another side beyond the line connecting the swing guide portion 70 and shaft rotating recess 73. The guiding notch 74 has an arched guiding surface 741 on a lower side. There is further a second retaining portion 72 between the guiding notch 74 and swing guide portion 70. The sinker 7 further has a groove 76 close to the shaft rotating recess 73 and an elastic tongue 77 between the groove 76 and shaft rotating recess 73. The sinker 7 thus formed can be made integrally so that design and structure are simpler and more durable. Material cost also is lower, thus the price can be reduced to meet market requirements.
FIGS. 5 and 6 show the sinker according to the present invention in use conditions. As shown in FIG. 5, when the downward pressing mechanism 1 is in operation, the cam holder 2 drives the cam 20 so that it moves horizontally. As the swing guide portion 70 of the sinker 7 is held in the guide track 21, the sinker 7 is driven by the curvature formed by the guide track 21. Moreover, as the shaft rotating recess 73 is coupled on the bracing shaft 4, the sinker 7 swings about the bracing shaft 4 as shown in FIG. 6; meanwhile, the second retaining portion 72 is in contact with the retaining rod 5 to let the sinker 7 stop swinging. When the downward pressing mechanism 1 continues operating, the cam holder 2 continuously drives the cam 20 so that it moves horizontally, and the swing guide portion 70 is still driven by the curvature formed by the guide track 21 to swing back as shown in FIG. 5; meanwhile, as the first retaining portion 71 is in contact with the bearing surface 11 of the needle seat 10, the sinker 7 stops swinging. Thus the downward pressing mechanism 1 can operate continuously and the cam 20 also is moved horizontally and continuously to drive all the sinkers 7 on the needle seat 10 so that they swing and press downward to form a knitted fabric.

Claims

A sinker for a flat knitting machine, comprising:
a shaft rotating recess (73) disposed at the bottom of said sinker (7);

a swing guide portion (70) extended outwards from an upper side of said sinker (7); and

a yarn pressing portion (75) protruded from one side of said sinker (7) beyond a line connecting the swing guide portion (70) and the shaft rotating recess (73) to press a yarn to form a knitted fabric;

said shaft rotating recess (73) comprising a shaft coupling portion (732) configured to couple with a bracing shaft (4);

characterized in that the sinker (7) further comprises a groove (76) close to the shaft rotating recess (73) and an elastic tongue (77) formed between the groove (76) and the shaft rotating recess (73), wherein

a neck (731) located at an entrance of the shaft coupling portion (732) is formed at an interval smaller than the maximum interval of the shaft coupling portion (732).
The sinker of claim 1, further comprising a first retaining portion (71) located between the shaft rotating recess (73) and the yarn pressing portion (75).
The sinker of claim 1 or 2, further comprising a guiding notch (74) at another side beyond the line connecting the swing guide portion (70) and the shaft rotating recess (73), the guiding notch (74) comprising an arched guiding surface (741) at a lower side, the guiding notch (74) and the swing guide portion (70) being interposed by a second retaining portion (72).
A downward pressing mechanism for a flat knitting machine for driving all sinkers (7) of said flat knitting machine to swing and press downwards said sinkers, comprising:
a needle seat (10) including a bearing surface (11) to hold said sinkers (7) and knitting needles (8) separated by spacers (3); and

a cam holder (2) located above the sinkers (7) to hold a cam (20); wherein

the cam (20) includes a guide track (21) to drive the sinkers (7) swinging, and

a bracing shaft (4) extends perpendicularly through the spacers (3) at a lower side thereof;

each sinker (7) comprising:
a shaft rotating recess (73) disposed at the bottom of said sinker (7) and comprising a shaft coupling portion (732) to couple with the bracing shaft (4);

a swing guide portion (70) extended outwards from an upper side of said sinker (7) and driven by the guide track (21); and

a yarn pressing portion (75) protruded from one side of said sinker (7) beyond a line connecting the swing guide portion (70) and the shaft rotating recess (73) for pressing a yarn to form a knitted fabric;

characterized in that each sinker further comprises a groove (76) close to the shaft rotating recess (73) and an elastic tongue (77) formed between the groove (76) and the shaft rotating recess (73), wherein

a neck (731) located at an entrance of the shaft coupling portion (732) is formed at an interval smaller than the maximum interval of the shaft coupling portion (732)
The downward pressing mechanism of claim 4, wherein a retaining rod (5) extends perpendicularly through the spacers (3) at an upper side thereof, each sinker (7) including a first retaining portion (71) restricted by the bearing surface (11) during rotating and swinging downward thereof and a second retaining portion (72) restricted by the retaining rod (5) during rotating and swinging upward thereof.
The downward pressing mechanism of claim 4 or 5, wherein a guiding rod (6) extends perpendicularly through the spacers (3), each sinker (7) including a guiding notch (74) which includes a guiding surface (741) to guide and limit rotating and swinging positions of the sinker (7).