A Presser Foot Module for A Tufting Machine

Abstract

A presser foot module (50) for a tufting machine. The module has a module body (13) for attachment to a tufting machine and the plurality of fingers (12) extending from the body in a first direction which, in use, is opposite to the direction in which the backing medium (1) is fed through the tufting machine. The module body (13) has a downwardly depending lip (53) defining a presser surface (53A) extending across an end of the body which is adjacent to the interface with the fingers (12). Each finger (12) has an unsupported end opposite to the module body (13) so as to provide access to an open gap between adjacent fingers in a direction opposite to the first direction.

Claims

1. A presser foot module for a tufting machine, the presser foot module having a module body for attachment to a tufting machine and a plurality of fingers with a pitch extending from the module body in a first direction which, in use, is opposite to a direction in which backing medium is fed through the tufting machine; wherein the module body has a downwardly depending lip defining a presser surface extending across an end of the module body which is adjacent to an interface with the fingers.

2. The presser foot module according to claim 1, wherein the downwardly depending lip has a dimension in the first direction, which dimension is less than 1.5 times the pitch of the fingers.

3. The presser foot module according to claim 2, wherein the dimension of the downwardly depending lip in the first direction is less than the pitch of the fingers.

4. The presser foot module according to claim 1, wherein the downwardly depending lip has a dimension in the first direction, wherein the dimension is greater than 0.5 times the pitch of the fingers.

5. A The presser foot module according to claim 1, wherein each finger has a first end mounted in the module body and a second end opposite to the first end which is unsupported so as to provide access to an open gap between adjacent fingers in a second direction opposite to the first direction.

6. The presser foot module according to claim 5, wherein a ratio of a maximum length of a finger to the pitch of the fingers is less than 4.

7. The presser foot module according to claim 6, wherein the ratio of the maximum length of a finger to the pitch of the fingers is less than 3.5.

8. The presser foot module according to claim 7, wherein the ratio of the maximum length of a finger to the pitch of the fingers is less than 3.

9. The presser foot module according to claim 1, wherein a lower edge of each finger has a groove.

10. A tufting machine comprising: a plurality of needles arranged on a first side of a plane along which, in use, a backing medium is fed through the machine in a first direction, the needles being reciprocable to penetrate the backing medium to form a loop of yarn on a second side of the plane; a plurality of hooks or loopers arranged on the second side of the plane to receive respective loops of yarn formed by the needles: at least one presser foot module arranged on the first side of the plane, the presser foot module having a module body for attachment to a tufting machine and a plurality of fingers extending from the module body in a first direction which, in use, is opposite to the direction in which the backing medium is fed through the tufting machine; wherein the module body has a downwardly depending lip defining a presser surface extending across an end of the module body which is adjacent to an interface with the fingers.

11. A presser foot module for a tufting machine, the module having a module body with a first side for attachment to a tufting machine and a plurality of fingers having a pitch room for extending from the module body in a first direction which, in use, is opposite to a direction in which backing medium is fed through the tufting machine, each finger having a first end mounted in the module body and a second end opposite to the first end which is unsupported so at to provide access to an open gap between adjacent fingers in a direction opposite to the first direction.

12. The presser foot module according to claim 11, wherein a lower edge of each finger has a groove.

13. The presser foot module according to claim 11, the presser foot module having a second side opposite to the first side provided with a presser surface extending across the module body to engage, in use, with a backing medium fed through the tufting machine.

14. The presser foot module according to any of claims 13, wherein the fingers do not extend below the presser surface; wherein at least part of the lower edge of each finger is greater than 0.5inin above the presser surface.

15. The presser foot module according to any of claims 14, wherein each finger is formed as a single planar component in a plane transverse to the presser surface.

16. The presser foot module according to any of claims 11, wherein a ratio of a maximum length of a finger to the pitch of the fingers is less than 4.

17. The presser foot module according to claim 16, wherein the ratio of the maximum length of a finger to the pitch of the fingers is less than 3.5.

18. The presser foot module according to claim 17, wherein the ratio of the maximum length of a finger to the pitch of the fingers is less than 3.

19. A tufting machine comprising: a plurality of needles arranged on a first side of a plane along which, in use, a backing medium is fed through the tufting machine, the needles being reciprocable to penetrate the backing medium to form a loop of yarn on a second side of the plane; a plurality of hooks or loopers arranged on the second side of the plane to receive respective loops of yarn formed by the needles: at least one presser foot module arranged on the first side of the plane, the module having a module body for attachment to a tufting machine and a plurality of fingers extending from the body in a first direction which, in use, is opposite to a direction in which the backing medium is fed through the tufting machine, each finger having a first end mounted in the module body and a second end opposite to the first end which is unsupported so at to provide access to an open gap between adjacent fingers in a direction opposite to the first direction; and wherein each finger is formed as a single planar component in a plane transverse to a presser surface of the modular body.

20. (canceled)

Description

[0018] An example of a presser foot module and a tufting machine in accordance with the present invention while now be described with reference to the accompanying drawings in which:

[0019] FIG. 1 is a side view of a tufting machine of the present invention;

[0020] FIG. 2A is a view from below showing a conventional presser foot module;

[0021] FIG. 2B is a similar view showing a presser foot module according to the present invention; and

[0022] FIG. 3 is a perspective view of a presser foot module according to the invention.

[0023] The tufting machine shown in FIG. 1 is, in almost every respect, a known individual needle control (ICN) machine. As this is largely conventional, the main components will be described briefly here.

[0024] The backing medium 1 (depicted schematically as a dashed line in FIG. 1) is fed through the tufting machine in a feed direction depicted by arrow 2 and is supported in the tufting position by a bed plate 3. A needle bar 4 supports a line of needles 5 (the line extending in the direction perpendicular to the plane of FIG. 1). Each needle 5 is supported on a needle support 6. Each needle support 6 has an associated latch 7 such that, if the needle 5 is required to be reciprocated in a particular stroke, the needle 5 can be selectively latched to the needle bar 4 so that it will penetrate the backing medium 1 to form a loop of yarn. This is well-known in the art as an individual needle control (ICN) machine.

[0025] Beneath the backing medium 1 is a looper 8 associated with each needle 5. The loopers 8 will rock forwards to pick up a loop of yarn formed by the needle 5. In this example, the loopers are preferably level cut loopers (LCL), these have a latching mechanism which is configured either to ensure that the loop of yarn slips off of the looper 8 or alternatively to ensure that it is retained on the looper 8 such that it slides back to a throat 9 of the looper and is cut by a respective knife 10 in order to form a cut pile tuft. This mechanism is therefore capable of selectively forming loop or cut pile tufts. Further details of a level cut looper are disclosed, for example, in GB 2367305 or GB 2354263.

[0026] In order to support the backing medium 1 as the needles 5 are pulled through it in the upwards direction in FIG. 1, a presser foot 11 is provided. This is mounted so as to shift laterally to following the movement of the needle bar 4. The presser foot comprises a plurality of fingers 12 and a mounting body 13.

[0027] Although the above described machine is an ICN machine, the presser module can also be used on a conventional tufting machine.

[0028] The presser foot module is shown in greater detail in FIGS. 2B and 3. These show one module 50 of the presser foot. As described above, this has a mounting body 13 from which a plurality of fingers 12 project in a direction opposite to the direction 2 in which the backing medium 1 is fed through the tufting machine. The body 13 is provided with a mounting hole 51 by which the presser foot module 50 is mounted to a presser foot bar 52 (FIG. 1) which is mounted to slide laterally together with the needle bar, but does not reciprocate with the needle bar in the direction of reciprocation of the needles. Instead, it remains in the position shown in FIG. 1 immediately above the backing medium 1.

[0029] The module 50 has three unconventional features.

[0030] Firstly, in the conventional presser foot module 50′ shown FIG. 2A, a bar 60 extends across the distal end of the FIG. 12′ in order to provide enhanced rigidity. In FIG. 2B, no such bar is present such that there is an open gap at the distal of the fingers 12. This improves the rethreading of the tufting machine as, when passing a yarn through the presser foot, this can be done by moving the yarn laterally between two fingers 12, rather than having two thread a cut end from top to bottom as previously. The replacement of a module is also easier.

[0031] The second modification is the presence of a downwardly depending lip 53 which extends across the module 50 in a downward direction (i.e. in a direction away from the service which is mounted to the presser foot bar 52) such that, in use, only this lip 53 engages with the yarns. As will be apparent from a comparison of FIGS. 2A and 2B, the presser surface 53A provided on the lower face of the lip 53 is significantly narrower than the presser surface 53B of the prior art and there is a wide region 53C behind the lip 53 where the yarns do not engage with the presser foot module.

[0032] As a third modification, the fingers 12 have been shortened. In particular, the ratio of the maximum length of a finger to the pitch of the fingers has been reduced from 4.3 to less than 4, more preferably less than 3.5 and most preferably less than 3. This saves material and reduces weight. Now that the bar is no longer required, the size of the opening between adjacent fingers is no longer an issue in the threading operation.

[0033] The lower edge of each finger 12 has a groove 14 which represents a region where the lower edge is spaced further from the backing medium 1. The finger therefore has a position of minimum height part way along its length and increases in height in both directions away from that position.

[0034] In use, the yarns extend down between adjacent fingers and the portions of the yarn which end up on the rear surface of the backing medium 1 then slide under the module body 13. The groove 14 allows the yarn to pass readily beneath the lower edge of the finger 12 and helps to keep it in place in a controlled position which is away from any stitch location of a subsequent stitch.

[0035] By providing the lip 53, rather than the yarn engaging surface across a wide portion of the module 13, the yarns only engage under the lip leading to a reduced frictional force between the presser foot and the yarn. Also, as the lip 53 represents a single line of contact between the presser foot and the yarn, it is easier to control the amount of pressure on the yarn. Control of this pressure is important and it requires a balance between creating a pressure which is high enough to ensure that the loose ends of yarn stay under the presser foot, but which is not high enough to generate undue friction on the yarns.