Variable stroke drive system for tufting machine

Patent metadata

Field	Value
Publication number	US-10358755-B2
Application number	US-201715589159-A
Country	US
Kind code	B2
Filing date	May 8, 2017
Priority date	Feb 28, 2014
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

A variable stroke drive system for a tufting machine includes a series of drive assemblies mounted along the frame of the tufting machine. Primary drive shafts extend through the drive assemblies and are each driven by a drive motor. A series of first drive members are mounted to the primary drive shafts and are linked to associated second drive members such that the driving of the first drive members by the primary drive shafts in turn drives the second drive members. Cam arms are connected to the second drive members and to rocker arms to which push rods are mounted, the cam arms being vertically reciprocated by the rotational movement of the second drive members so as to drive the reciprocation of the push rods, and thus the needle bar(s) connected thereto along a desired stroke or reciprocating path of travel. Controlling the rate at which the primary drive shafts are driven enables control of the stroke of the needle bar(s).

First claim

What is claimed is:

1. A tufting machine, comprising:
a frame;
at least one needle bar reciprocable toward and away from the backing material and having a series of spaced needles therealong for forming tufts of yarns in the backing material;
a variable needle bar drive system for driving the at least one needle bar of the tufting machine in a reciprocating motion along a selected stroke, the needle bar drive system including a plurality of drive assemblies mounted in spaced series across the frame of the tufting machine, each drive assembly comprising:
a pair of first drive members each linked to a drive shaft whereby each of the first drive members is driven by operation of a motor;
a pair of second drive members each linked to an associated one of the first drive members so as to be driven thereby;
cam arms, coupled to the second drive members;
a rocker arm located between the cam arms; and
a push rod having a proximal end attached to the rocker arm and a distal end linked to the needle bar of the tufting machine, the push rod moving the needle bar along its stroke;

wherein as the first drive members of each drive assembly are driven, the cam arms are moved in a substantially reciprocating motion for driving the push rod, and thus the needle bar along its stroke in a substantially reciprocating movement, and wherein as the first drive members are driven at varying rates, the movement of each cam arm of each of the drive assemblies is varied so as to change the stroke of the needle bar.

2. The variable drive system of claim 1 , further comprising drive belts or chains linking each first drive member to an associated one of the second drive members.

3. The variable drive system of claim 1 , wherein the proximal ends of the cam arms are each mounted to the second drive members at an off-center location.

4. The variable drive system of claim 1 , further comprising a pair of variable speed drive motors each operatively connected to a drive shaft to which one of the first drive members of each drive assembly is linked.

5. The tufting machine of claim 1 , further comprising at least 4 variable speed motors, coupled to each of a series of the drive assemblies by a series of connected drive shafts.

6. The tufting machine of claim 1 , further comprising a yarn feed mechanism for selectively controlling feeding of yarns to the needles of the needle bar for forming tufts of yarns in the backing material as the needles are reciprocated into engagement with the backing material.

7. A method of operating a tufting machine to form tufted articles, comprising:
moving a backing material through the tufting machine;
operating a plurality of drive assemblies, each drive assembly comprising a series of drive gears, cam arms drivingly connected to the drive gears so as to be moved in a substantially linear reciprocating motion by rotation of the drive gears, a rocker arm extending between the cam arms, and a push rod pivotally mounted along an intermediate portion of the rocker arm and connected to at least one needle bar for imparting the substantially linear reciprocating motion of the cam arms to the at least one needle bar to reciprocate a series of needles mounted along the at least one needle bar toward and away from the backing material;
feeding yarns to the needles carried by the at least one needle bar for forming a series of tufts in the backing material;
varying a rate at which selected ones of the drive gears are rotated; and
in response to varying the rate of rotation of the selected ones of the drive gears, reorienting the rocker arms of the drive assemblies with respect to the pusher rods mounted thereto so as to adjust a length of stroke of the needle bar.

8. The method of claim 7 , wherein varying the rate at which selected ones of the series of drive gears are rotated comprises operating drive motors coupled to first drive gears of the series of drive gears at different rates.

9. The method of claim 7 , wherein varying the rate at which selected ones of the drive gears are rotated further comprises adjusting the rate of rotation of the selected ones of drive gears during a stitch cycle to adjust a dwell time of the needles during reciprocation thereof.

10. The method of claim 7 , further comprising shifting the at least one needle bar in a direction transverse to the movement of the backing material through the tufting zone.

11. The method of claim 7 , further comprising varying the feeding of at least selected yarns to the needles so as to pull the selected yarns low or out of the backing material.

12. The method of claim 7 , wherein reorienting the rocker arms comprises driving the cam arms of each pair of cam arms between which the rocker arms are mounted in an out-of-phase relationship to cause pivoting of the rocker arms with respect to the push rods.

13. The method of claim 7 , further comprising engaging the needles with a series of loop pile loopers, cut pile hooks or level cut loop loopers as the needles are reciprocated into the backing material to form a series of loop and/or cut pile tufts.

Assignees

• Card Monroe Corp

Inventors

• Mathews Ricky E

Classifications

• D05B69/12

  using rotary electric motors · CPC title

• D05C15/32

  by altering the loop length · CPC title

• D05C15/20 Primary

  Arrangements or devices, e.g. needles, for inserting loops; Driving mechanisms therefor · CPC title

• D05C15/12

  in more than one row · CPC title

• D05C15/00

  Making pile fabrics or articles having similar surface features by inserting loops into a base material (layered products B32B; non-woven pile fabrics D04H11/00) · CPC title