MECHANISM FOR DRIVING THE NIPPER ASSEMBLY OF A MULTI HEAD COMBING MACHINE

FIELD OF THE INVENTION

[001] The present invention generally relates to a spinning preparatory machine, more particularly a combing machine to provide an improved driving arrangement for driving the individual nipper assembly.

PRIOR ART

[002] A combing machine produces a thin sheet composed of fibers, referred to herein as "fleece", by removing short fibers from a group of fibers, referred to herein as "lap", in the manufacturing process of cotton yam. The average length of cotton fiber depends on its kind or its place of origin. Additionally, even in the same kind of cotton, its average fiber length is not constant and often varies. To produce high-grade cotton yarn with superior tenacity and appearance, it is necessary to remove short cotton fibers including foreign matters and neps.

[003] Generally, a textile combing machine comprises a plurality of combing heads, each combing head having a combing cylinder, a top comb, a pair of detaching rollers and a nipper apparatus. The nipper apparatus rocks back and forth while nipping lap supplied thereto. The combing cylinder, also referred to as half lap has a series of saw-toothed wires embedded on its peripheral surface. As the nipper apparatus moves backward, the saw toothed wires perform a combing action at the forward end of the lap. This combing action removes short fibers from the lap, producing a fleece. As the nipper apparatus moves forward towards the detaching rollers, the fleece is transferred forward. The fleece from the combing heads are doubled and drafted in the drafting arrangement of the combing machine. The drafted fibers are converted as sliver and are deposited in sliver cans.

[004] In general, the nipper apparatus comprises a bottom nipper bracket, a bottom nipper fixed on the bottom nipper bracket at its front end, and a top nipper to nip the lap in cooperation with the top plate. The top nipper nips the lap at the tip of the cushion plate. The nipper frame can rock between a back most position where the tip of the bottom nipper is proximate to the combing cylinder clothed with saw toothed wires and a foremost position where the said tip is proximate to the detaching rollers.

[005] One such textile fiber combing machine disclosed in US
Patent No.3600758 assigned to Maremont Corporation relates to a nipper assembly drive having two cooperating eccentric elements which makes it possible to establish an adjustable predetermined stroke of the nipper assembly from a generally unchanged back position of the nipper assembly. This adjustment is made particularly convenient by the utilization of indicia for each of the eccentric members, which cooperate with one another to provide such adjustment. In the Maremont patent, the bottom nipper bracket is driven by a nipper shaft located parallel to the comb shaft, and is supported by the comb shaft in a rockable manner by suitable drive means, for example, a four-bar link mechanism or gear linkage mechanism or slider crank mechanism. The comb shaft is driven through the driving mechanism arranged in the headstock, which is driven by the driving element such as motor. The oscillating nipper shaft is driven by the comb shaft in a rockable manner through said drive means such as four-bar link mechanism or gear linkage mechanism or slider crank mechanism.

[006] In such kind of nipper drive arrangement, lengthy nipper drive shaft is provided in which the individual nipper assemblies are mounted at each combing heads. This type of arrangement is suitable for lower nipping speeds and suitable for up to 8 combing heads. In order to achieve high production, the said speed and number of combing heads are to be increased. This results in occurrence of torsional natural frequency, which will create detrimental effect in mechanical components as well as fibre combing function. It also results in enormous reaction forces at the drive end, which produces considerable vibration in the headstock of the machine. The closing and opening time of nippers in each head would not synchronize due to the reduced stiffness of nipper shaft, which tends to twist the nipper shaft. In addition, the power consumption of existing combing machines is comparatively high due to the weight of oscillating nipper shaft, which are disadvantageous.

[007] There is a need for a nipper drive arrangement for individual nippers to eliminate the conventional lengthy nipper shaft, which runs longitudinally to the entire length of the combing machine. There is also a need for a nipper drive arrangement that will facilitate the increase in production of sliver.

OBJECT OF THE INVENTION

[008] One object of the invention is to provide an improved nipper drive arrangement for a textile fiber-combing machine, which will facilitate the increase in the number of combing head units.

[009] Another object of the invention is to provide an improved nipper drive arrangement for a textile fiber-combing machine with increased working speed that will result in increase in productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 shows the mechanism for driving the nipper assembly of a textile fiber combing machine driving a plurality of combing heads according to an embodiment of the invention.

[0011] FIG- 2 shows an exploded view of a single comb head unit of a textile fiber combing machine incorporating the improved nipper drive arrangement according to an embodiment of the invention.

[0012] FIG - 3 shows the drive elements adopted for driving the nipper assembly of a combing machine according to an embodiment of the invention.

[0013] FIG - 4 depicts the nipper assembly known in the art.

SUMMARY OF THE INVENTION

[0014] One aspect of the invention includes an improved driving arrangement for driving the individual nipper assembly. The nipper drive arrangement for a combing head in a textile machine includes a comb drive shaft. A plurality of nipper assembly is mounted in each combing head . The plurality of nipper drive shafts receives the drive from comb drive shaft.

[0015] Another aspect of the invention includes a textile fiber- combing machine, a plurality of nipper drive shafts are provided which receives the drive from comb drive shaft.

DETAILED DESCRIPTION OF INVENTION

[0016] Various embodiments of the invention provide a nipper drive arrangement for a textile fiber combing machine. FIG 1 shows the mechanism for driving the nipper assembly of a textile fiber combing machine driving a plurality of combing heads according to an embodiment of the invention. The combing machine comprises a plurality of combing heads. Each combing head is provided with a driving arrangement, which is capable of converting the rotary motion of the comb drive shaft (1) into oscillatory motion of the nipper drive shaft (5) to drive the nipper assembly (7).

[0017] FIG- 2 shows an exploded view of a single comb head unit of a textile fiber combing machine incorporating the improved nipper drive arrangement according to an embodiment of the invention.

[0018] The mechanism for driving the nipper assembly according to an embodiment of the invention is explained herein below. As shown in FIG. 1 & 2, half lap or comb drive shaft (1), which is common to all the combing heads is arranged along the longitudinal direction of the combing machine to provide oscillatory motion to the nippers (7) as well as for the mounting of combing cylinders (not shown) of the combing heads. The half lap drive shaft (I) is connected to a driving source (not shown) so as to be positively driven at a predetermined unidirectional constant or variable angular velocity.

[0019] Each combing head is provided with a driving arrangement, which is capable of converting the rotary motion of the half lap drive shaft (1) into an oscillatory motion of the nipper drive shaft (5) to drive the nipper assembly (7). The individual elements associated with the above drive arrangement are shown In FIG 2 & 3. This drive arrangement comprises eccentric cam (2) which is rigidly mounted on the comb drive shaft (1). A connecting lever (3) is disposed to connect the eccentric cam (2) and a swing lever (4).

[0020] Referring to FIG 3, the bigger end (3a) of the connecting lever (3) is rotatably mounted over the eccentric cam (2) and the smaller end (3b) of the connecting lever (3) is pivotally connected to the smaller end (4a) of the swing lever (4) at pivot point (PI). A plurality of nipper drive shaft (5) which is pivotally mounted on the bearing in the frame and the said nipper drive shaft (5) receives the drive from comb drive shaft (1).

[0021] The nipper drive shaft (5) may be made of solid cylindrical material or hollow cylindrical material.. The bigger end (4b) of the swing lever (4) is rigidly fixed with the nipper drive shaft (5) in between two nipper cranks (6, 6') by using connecting element for example, keys. The nipper cranks (6, 6') are rigidity mounted on the nipper drive shaft (5), by using a connecting element for example keys. The said nipper cranks'(6, 6') together can be provided for a single nipper assembly (7) or can be provided as individual cranks for adjacent nipper assemblies (refer FIG I).

[0022] The small end of each of nipper cranks (6, 6') are pivotally connected to the rear end of the bottom nipper brackets at pivot points (P2, P2') as shown in FIG I & 2, to transmit the oscillatory motion from the nipper drive shaft (5) to the bottom nipper (8) of the nipper assembly (7). As well as the top nipper (9) of the nipper assembly (7) is connected to the bottom nipper (8) as known in the art. Further the top nipper (9) is drivingly connected and driven by any one of the methods known in the art, to facilitate gripping of the of the fibre material during the combing operation and for subsequent ungripping of the material for further processing by the combing machine.

[0023] The oscillatory motion is generated for a predetermined angle by rotating the comb drive shaft (I) uni-directionally and the same is transmitted to the plurality of nipper drive shaft (5) through the eccentric cam (2), connecting lever (3) and the swing lever (4). Since nipper crank (6, 6') is rigidly connected to the nipper drive shaft (5), it incorporates to and fro motion to the nipper assembly (7). The mechanism for driving the nipper assembly of a combing machine according to the invention employs a plurality of nipper drive shaft (5) of shorter length. The said drive system produces minimum vibration and consumes reduced power and the possibility of torsional vibration of oscillating nipper shaft is eliminated. The synchronization of all the combing heads is ensured.

[0024] As shown in Figure 4, it is known that each combing head is provided with an oscillating nipper assembly (7) comprising bottom nipper (8) and top nipper (9). The oscillating nipper assembly is located above the combing cylinder (not shown) and is rocked back and forth to facilitate combing of the fiber material held between the jaws of bottom nipper (8) and top nipper (9).

[0025] The invention, as described herein and as illustrated by diagram provides an improved nipper drive arrangement for a textile fiber combing machine comprising of a plurality of nipper assembly wherein a plurality of nipper drive shafts are provided which receives the drive from comb drive shaft. The mounting of the plurality of nipper drive shafts significantly reduces the vibration of the combing unit during operation due to the reduced weight and dimension of the nipper drive shaft. The productivity is increased by increased conversion rate of lap to sliver. The conversion of the lap into the sliver occurs at a rate of greater than 500nips/min. Even at lower speeds the productivity can be increased by increasing the number of combing heads.

[0026] The foregoing description of the invention has been set for merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

We claim:

1. A textile fiber combing machine comprising a plurality of combing heads mounted on a comb drive shaft characterized in that a plurality of nipper drive shafts are provided which receives the drive from comb drive shaft.

2. The textile fiber combing machine according to claim 1, wherein the nipper drive shaft is mounted onto the combing head for driving the nipper assembly.

3. The textile fiber combing machine according to claim 2, wherein the nipper assembly comprises of an eccentric cam, a connecting lever, a swing lever and a nipper crank.

4. A nipper drive arrangement for a combing head in a textile machine mounted on a comb drive shaft, the drive arrangement comprising of a nipper assembly mounted on each combing head characterized in that a plurality of nipper drive shafts are provided which receives the drive from comb drive shaft.

5. The nipper drive arrangement according to claim 4, wherein the nipper drive shaft is mounted onto the combing head for driving the nipper assembly.

6. The nipper drive arrangement according to claim 4, wherein the nipper assembly comprises an eccentric cam, a connecting lever, a swing lever and a nipper crank.

7. The nipper drive arrangement according to claim 4, wherein the nipper drive shaft is a solid or a hollow cylindrical material.

8. A nipper drive arrangement for a combing head in a textile machine substantially as herein described with reference to the accompanying drawings.