GB2354263A - A tufting machine having gated hooks - Google Patents

Abstract

A multi-cylinder module 90 has a common block, within which the cylinders are formed and having a piston 95 disposed within each cylinder and an output rod 94 connected to each piston. Pressurized air acts on the piston against the bias of a corresponding spring to drive the respective rod outwardly from the module. Each rod has a coupling member which is coupled to the gate 46 of a hook 44 of a tufting machine having gated hooks for forming both loop and cut pile. The modules 90 are mounted directly to the hook bar of the tufting machine and require no additional linkages between the coupling and the gate with the inherent lost motion and other inefficiencies associated with such additional linkages.

Description

2354263 A TUFTING MACHINE This invention relates to tufting machines and

more particularly to a method and apparatus for selectively forming cut pile and loop pile ha7ing substantially the same pile height as the cut pile in the same row of stitching in a backing material.

In US-A-4,134,347 and US-A-4,185,569, a method and apparatus for forming cut pile and loop pile which are substantially the same pile height in the same row of stitching are disclosed. These patents represent improvement over US-A-3,084,645 wherein the cut pile projects substantially further from the backing than the loop pile and thus the pile height differs substantially. In US-A-2,879,728 and 2,879,729, prior attempts to provide level cut and loop pile were made without success. The inventions in the aforesaid US A-4,134,347 and US-A-4,185,569 have been and remain very successful. This is especially true of variations of the sliding gate structure of the second embodiment illustrated in Figs. 7-11 of US-A-4,185,569 wherein the gate slides and cooperates with the bill of the hook to open or close passage of a seized loop from the bill to the blade selectively. Those loops released from the bill remain uncut while those loops which pass to the closed end of the hook are cut.

One of the problems with the sliding gate structure, which does not occur with a pivoted gate as in US-A-4,134,347, and the first embodiment o--" US-A 4,185,569, wherein the gate pivots on the hook, is that, since there is lateral movement of the gate driving mechanism, vertical support must be provided.

in the second embodiment of US-A-4,185,569 and variations o.-" this in the prior art, there must be an extension connected to the sliding gate or to the I equivalent such as a sliding cut/loop clip. In US-A4,185,569 which for practical reasons was not reduced to practice, this comprises a slide block supported on a fixed member of the tufting machine but in apparatus constructed in the prior art, this comprised of an extension member between the gate and the driving air cylinders which move with the hook bar as the hook rocks or oscillates. These extension members have to be supported on a member fastened to and movable with the hook backing bar and the cylinder support.

According to the present invention, there is provided a tufting machine comprising a housing; a needle bar which is reciprocably operable in a needle plane within the housing and on which a plurality of needles are mounted, a hook associated with each needle for engaging with each loop of yarn formed by the respective needle, in use, as a backing medium is fed through the machine; a clip associated with each hook which is selectively movable relatively to the hook in a direction perpendicular to the needle plane so as to selectively retain loops on yarn on the hook, and an actuator for moving each respective clip relatively to the respective hook, each actuator having a movable actuator member which is directly coupled to the respective clip without an intervening linkage member.

This arrangement reduces the complexity of the link between the actuator and clip. This reduces the overall mass to be reciprocated as it allows the actuator member to be brought generally into alignment with the clips, and also reduces the lost motion between the actuator and clio.

In the arrangement, the clips could be fixed to the actuator members so as to be part of an actuator module. However, the current preference is for the clips to be associated with the module, and for the coupling between the actuators and modules to be done in situ.

Preferably, the actuators are arranged in two rows, with one row being offset with respect to the other by half the distance between adjacent actuators. This staggered arrangement allows actuators to be brought closer together in the transverse direction of the machine, while the actuator members still remain substantially in line with the clip.

In order to reduce further the mass to be reciprocated on the hook bar, the actuators are preferably directly connected to the hook bar. This eliminates the intervening spacer members of the prior art.

A plurality of actuators are preferably grouped together in a single housing forming an actuator module. This facilitates the ease of assembly of the tufting machine.

Preferably, each actuator has an actuating mechanism to move each actuator member independently, a port connection to a source o-F motive power, and a connector for connecting the module to the tufting machine, the housing having a two-part construction, the two parts being releasalzly connected together w-Lth the 'L--rst part having the ports, and the second part housing the actuator members.

."his construction facilitates the maintenance o-IL: a tufting machine. If a fault should occur with one of the actuators, the module in which the fault occurs can be disconnected from the tufting machine. The two parts of the housing can then be detached from one another, and the second part of the housing can be replaced with a new second part which is attached to the first part. The advantage of this is that the connections to the source of motive power for all of the actuators in a particular module can be left in place while the second part of the housing is replaced. There is no danger with this approach of incorrectly connecting an actuator to the wrong source of motive power. There is therefore no need to test that all connections are correct following the replacement of a module so that the maintenance is process is greatly improved.

This forms the second aspect of the invention which may be defined in the broadest sense as an actuator module for moving a plurality of clips reciprocally with respect to a corresponding plurality of hooks in a tufting machine, the module comprising a housing containing a plurality of actuators, one for each clip, each actuator having an actuator member which is movable to move the clip, an actuating mechanism to move each actuator member independently, port for connection to a source of motive power, and connector for connecting the module to the tufting machine, the housing having a two-part construction, the two parts being releasably connected together, with the first part having the port, and the second part having the actuator members.

The actuator members may be actuated electrically or hydraulically, but the current prefference is for pneumatic actuation. In this case, the ac-tu-ator members are preferably pistons which are _reciprocablly movable within the housing which forms a plurality of 4 cylinders. A return spring is preferably provided for each actuator member to urge the actuator member into a retracted position.

An example of a tufting machine in accordance with the present invention will now be described with reference to the accompanying drawings, in which:

Fig. 1 is a vertical sectional view taken transversely through a multiple needle tufting machine illustrating certain features in diagrammatic form; Fig. 2 is a fragmentary vertical sectional view of a portion of a tufting machine illustrating the prior art hook and gate mounting structure;

Fig. 3 is a fragmentary vertical sectional view of a portion of the tufting machine illustrated in Fig. 1, but enlarged to show the hook and gate mounting structure constructed in accordance with the present invention; and Fig. 4 is a perspective view of a cylinder module partly broken away constructed in accordance with the principles of the present invention and illustrating one coupling member exploded out from the module.

Fig. 5 is an enlarged sectional view of a portion of the tufting machine of Fig. 3 from the opposite side to Fig. 3.

Referring now to the drawings, Fig. 1 illustrates 4 a tufting machine 10 having a frame comprsing a bed 12 and a head 14 disposed above the bed. The bed 12 includes a bed plate 16 having a support finger plate I'/ across which fabric F -'s adapted to be fed in the direction illustrated by a pair of input feed rolls 18 and output or take-off rolls 20.

Mounted in the head for vertical reciprocation is one of a plurality of push rods 22 to the lower end of which a needle bar 24 is carried and which in turn carries a plurality of needles 26 which are adapted to penetrate the fabric F through fingers in the support finger plate 17 upon reciprocation of the needle bar 24 to project loops of yarn therethrough. A reciprocating motion is imparted to the ends of the push rods 22 and thus the needle bar 24 and needles 26 by a connecting rod 28 which is pivotally connected at its lower end to the push rods 22 and at its upper. end to an eccentric 30 on a driven rotary main shaft 32 that is journalled longitudinally in the head 14. A pressure foot assembly 34 may be supported on the head 14 to hold down the fabric F during needle retraction. A yarn-jerker 36 is carried by the needle bar 24 and operates to engage the yarn between a stationary yarn guide 38 on frame of the machine and the needles 26.

Yarn Y is supplied to each needle 26 by a conventional type of yarn feed mechanism including a pair of feed rolls 40, 42 mounted on the head 14 and adapted to be continuously rotated by any convenient means preferably synchronized with the main shaft 32 to continuously feed lengths of yarn to the needles. The amount of yarn fed to the needles is less than that demanded by the system so that yarn is pulled back from each looo after is has been formed as eac-, stitch is tightened and set into the fabric IF.

Mounted within the bed for cooperation with the needles to seize loops of yarn presented thereto are a plurality of loopers; or gated hooks generally indicated at 44 and as hereinar--er described in conjunction with Fig. 3. The hooks as hereinafter 6 made clear are of the cut pile type which point in the direction opposite to that which the fabric is fed, and additionally carry a sliding gate as hereinafter described. The hooks preferably are mounted in modules 48 similar to those modules disclosed in US-A4,739,717 which are connected to a mounting bar 49 secured to the upper end of a rocker arm 50. Any conventional means to oscillate the arm 50 may be provided. It is preferred that the lower end of the rocker arm 50 is clamped to a laterally extending rocker shaft 52 journalled in the bed. Pivotally connected to the upper portion of the rocker arm 50 is one end of the connecting link 54 having its other end pivotally connected between forked arms of a jack shaft rocker arm 56. The arm 56 is clamped to a jack shaft 58 which has oscillating motion imparted thereto by a conventional drive means such as a cam and lever means (not shown) from the main shaft 32 in timed relationship with the reciprocation of the needles.

The tufting machine incorporates a plurality of knives 60 which may cooperate with the hooks that cut the selected loops thereon to form cut pile as he--einafter described. The knives may be mounted in knife blocks 62 secured to a knife bar 64 which in turn is secured to a knife shaft rocker arm 66 clamped to a knife shaft 68 to conventionally drive the knives into engagement with one side of the respective hooks as known in the art to provide a scissors-like cutting action.

As illustrated in Fig. 2, in the prior art the gated hooks 44 and the associated modules 48 within which a plurality of hooks are mounted have the gate

46 slidably moun-Led within a slot --Formed in the hook to open and close the bi-1-1 of the hook, the zail of the gate being connected through a linkage 70 7 including a link 71 and a block 72 fastened to the output rod of the respective pneumatic cylinder 74. Due to space limitations, the cylinders were mounted in a vertical stack with the cylinder 74 supported in a frame 76 and the blocks 72 of adjacent cylinders offset vertically so that a coupling pin 78 on each block may cooperate with a slot 80 in the cooperating end of a respective link 71, the links of alternate hooks 44 differing so that the block connecting portions of alternate links are spaced not only laterally but vertically as illustrated.

The hook mounting bar 49 must be connected to a support member 82 by means of a spacer member 84 is therebetween and is in turn connected to the cylinder support frame 76 by another spacer member 86. A cover member 88, which is required to protect the apparatus from lint due to the environment in which it operates is connected to the support member 82 and to the frame 76. The elements illustrated in Fig. 2 oscillate with the hook mounting bar drive as aforesaid. Thus, it may be readily understood that since all of these elements are constructed from steel, a very heavy mass must be oscillated, and also the multitude o--': elements require substantial assembly time during manufacture and both disassembly and assembly time during maintenance.

To overcome -these disadvantages of the prior ar-L.

the present invention provides a cylinder module 90 illustrated in Figs. 3 to 5, the module comprising a housing constructed from two body members 91, 93 formed from aluminum allov so as to be light in weight and carry a plurality of oneumatic cylinders (not illustrated) fed with air from respec-live nizoles 92 and having piston driven output rocis 914. The body member 91 has cylindrical chambers fo-- med therein and 8 receives the pistons 95 with the rods extending out the end remote from the body member 933, the latter having the input nipples 92. A spring 97 biases the rods inwardly. The cylinders and thus the output rods 94 are arr'anged in two vertical spaced apart rows with the cylinders in one row staggered relative to those in the other row with each rod terminating in a coupling member 96 rigidly fixed to the end of each rod. In preferred forms of the module there are twenty cylinders in an 1/8 gauge machine and twenty four cylinders in a 1/10 gauge machine and half of the cylinders are in each row. Disposed at each lateral end integral with the lower surface of the module is a respective tube 99 (only one of which is shown) within which a screw 101 extends for securing the module to the mounting bar 49. Alternatively, the cylinders may be arranged in a single line. In this case, the cylinder could have a square cross section to allow the cylinders to be close enough together that they do not need to be staggered.

The two body members 91, 93 are releasably joined together by a pair of screws 91A. In order to replace a module with a faulty actuator, the screw 101 is first undone to release the module from the machine. The two screws 91A are then unscrewed so that the body member 91 containing the pistons 95 and springs 97 can be removed and replaced. The replacement body member is simply screwed in place by the screws 91A and the module is then reattached to the machine. During this replacement, the pneumatic connections remain attac - ned to the input nipples 92, so that there is no nee-; to -ic connect4ons once the reQlacement tesr- the pneumall 4 module is in place. The faulty module can e-L-Lher be repaired or discarded.

Each of the coupling members 96 includes a slot 9 98 with an internal nub 100. The nub 100 is adapted to be received within and coupled with a complementary recess formed in the tail end 104 of the gate 46 so that the gate may move with the cylinder rod of the respective cylinder. In the preferred embodiment, the cylinder rod extends when pressurized air is supplied to the corresponding cylinder and retracts into the cylinder by virtue of a spring internal to the cylinder when the pressure is released. A cover 106 preferably may overlie the module, the rods and the tail end of the gate for the same purpose as in the prior art.

As is known in the prior art when the gate is extended the hook is closed and the loop which has been seized is released to form loop pile, but when the gate is retraced the loop may enter the blade of the hook and move toward the throat at the closed end where it is cut by the knife 60 to form cut pile.

The control of the air cylinders and thus the gates may be via a programmed computer 108 supplying signals to valves 110, the number of valves preferably corresponding to the cylinders so that each hook in the tufting machine is controlled individually, the valves opening and closing communication between a compressor 112 and air conduits 114 communicating the valves with the cylinders in the module. As understood by those skilled in the art, there will be a plurality of such modules across the tufting machine which may have some 1000 or more hooks coccerating with an equal number of needles.

Claims (9)

1. A tufting machine comprising a housing; a needle bar which is reciprocably operable in a needle plane within the housing and on which a plurality of needles are mounted, a hook associated with each needle for engaging with each loop of yarn formed by the respective needle, in use, as a backing medium is fed through the machine; a clip associated with each hook which is selectively movable relatively to the hook in a direction perpendicular to the needle plane so as to selectively retain loops on yarn on the hook, and an actuator for moving each respective clip relatively to the respective hook, each actuator having a movable actuator member which is directly coupled to the respective clip without an intervening linkage member.

2. A tufting machine according to claim 1, wherein the actuators are arranged in two rows, with one row being offset with respect to the other by half the distance between adjacent actuators.

3. A tufting machine according to claims 1 or claim 2, wherein the actuators are directly connected to the hook bar.

4. A tufting machine according to any one of the preceding claims, wherein a plurality of actuators are grouped together in a single housing forming an actuator module.

5. A tufting machine according to claim 4, wherein each actuator has an actuating mechanism to I I move each actuator member independently, a port connection to a source of motive power, and a connector for connecting the module to the tufting machine, the housing having a two-part construction, the two parts being releasably connected together with the first part having the ports, and the second part housing the actuator members.

6. An actuator module for moving a plurality of clips reciprocally with respect to a corresponding plurality of hooks in a tufting machine, the module comprising a housing containing a plurality of actuators, one for each clip, each actuator having an actuator member which is movable to move the clip, an actuating mechanism to move each actuator member independently, a port for connection to a source of motive power, and a connector for connecting the module to the tufting machine, the housing having a two- part construction, the two parts being releasably connected together, with the first part having the port, and the second part having the actuator members.

7. An actuator module according to claim 6, wherein the actuator members are pneumatic.

8. An actuator module according to claim 7, wherein each actuator member is a piston which is reciprocably movable within the housing which forms a plurality of cylinders.

9. An actuator module according to claim 8, wherein a return spring is provided for each actuator member to urqe the actuator member into a retracted position.

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