US3460499A

US3460499A - Needle-bar throwout mechanism for tufting machine

Info

Publication number: US3460499A
Application number: US706248A
Authority: US
Inventors: William M Gaines
Original assignee: Singer Co
Current assignee: SPENCER WRIGHT INDUSTRIES Inc A CORP OF TENNESSEE; Singer Co
Priority date: 1968-02-19
Filing date: 1968-02-19
Publication date: 1969-08-12
Anticipated expiration: 1986-08-12
Also published as: GB1188925A

Description

Aug. 12, 1969 w. M. GAINES NEEDLE-BAR THROWOUT MECHANISM FOR A TUF'IING MACHINE Filed Feb. 19, 1968 2 Sheets-Sheet 1 4 m NW w WM m .w W

ATWORNEY WITNESS: 6 0b Jolwgg Aug. 12, 1969 W.M. GAINES NEEDLE-BAR THROWOUT MECHANISM FOR A TUFTIN G MACHINE Filed Feb. 19, 1968 2 SheetS 'Sheet'Z INVENTQR. wlllmm M. Games ORN EX United States Patent 3,460,499 NEEDLE-BAR THROWOUT MECHANISM FOR TUFTING MACHINE William M. Gaines, Lafayette, Ga., assignor to The Singer Company, New York, N.Y., a corporation of New ersey Filed Feb. 19, 1968, Ser. No. 706,248 Int. Cl. Dh 69/22 US. Cl. 112-221 6 Claims ABSTRACT OF THE DISCLOSURE An operator actuated mechanism for a tufting machine for disengaging the needle-bar from the needle-bar driving collar, including latch fingers carried on the needle bar for providing a driving connection between the needlebar driving collar and the needle-bar, and an unlatching member utilized to operate the latch fingers to disengage the needle-bar from the needle-bar driving collar. Mechanism including a spring biased braking member is utilized to hold the needle-bar in a raised position after it has been disengaged from the needle-bar driving collar.

Background of the invention In some of the prior art tufting machines such as that disclosed in the United States Patent No. 2,314,339, Mar. 23, 1943, R. H. Bradwell, operator influenced mechanism is included for disconnecting the needle-bar from its drive means. The Bradwell patent also includes mechanism for holding the needle-bar in a raised position after it has been disconnected from its drive elements. In the Bradwell patent, there is disclosed a pivotal connecting arm carried by the needle-bar one end of which operatively connects the needle-bar to the drive means. In addition, the Bradwell mechanism includes a manually operable latch arm pivotally mounted in the tufting machine head and adapted to pivot the connecting arm to disengage the needle-bar from its drive means and hold the needle-bar in a raised position.

In the Bradwell mechanism when the needle-bar reconnecting means is actuated it is possible for the needlebar to drift downwardly before the drive means is reengaged with the needle-bar. When this occurs the drive means and the needle-bar are reengaged at a point in the endwise reciprocatory cycle of the drive means when the drive means is moving at a relatively high speed. The resultant jarring impact as the needle-bar and the drive means engage at such a relatively high speed could result in damage to the pertinent machine parts and in addition results in a loud annoying clatter. Another drawback disclosed in the Bradwell patent is that the operative connection between the needle-bar and the needle-bar drive means consists of only one arm which makes the connection on one side only of the needle-bar thereby exerting a side thrust during normal operation on the needle-bar which causes abnormal needle-bar bearing wear.

Summary of the invention ing the force applied on the needle-bar. In addition, the

operative connection between the needle-bar and the driving collar includes two oppositely disposed pivotally mounted fingers carried by the needle-bar.

The described embodiment of the present invention avoids the drawbacks of the prior art mechanism briefly outlined above by utilizing resilient means for gradually releasing the braking force applied to the needle-bar thereby preventing the needle-bar from drifting downwardly before the needle-bar is reengaged with the driving means, thereby obviating any jarring shocks to the pertinent machine elements and the attendant annoying clatter. In addition, the provision of the two oppositely disposed fingers connecting the needle-bar to the needlebar driving collar obviates the side thrust exerted on the needle-bar during normal operation as is the case in the Bradwell mechanism.

It is an object of this invention to provide an improved mechanism tor disengaging the needle'bar from the needle-bar driving collar in any machine having such needle-bar mechanism.

It is another object of this invention to provide an improved mechanism for holding the needle-bar in a raised position after it has been disengaged from the needle-bar driving collar.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings.

Brief description of the drawings FIG. 1 is a side elevational view of a. tufting machine embodying the present invention.

FIG. 2 is a skeletonized perspective view of elements of the present invention positioned in the head of the tufting machine shown in FIG. 1.

FIG. 3 is an elevational head-end view of the tufting machine shown in FIG. 1.

FIG. 4 is an enlarged view of the section taken substantially along line 4--4 of FIG. 3.

Description of the preferred embodiment With reference to the drawings there is illustrated a single needle tufting machine 10 having a frame formed with a bed 12 from one end of which rises a standard 14 that supports an arm 16 terminating in a head 18 above the bed 12. A rotary arm shaft 20 is journaled longitudinally of the arm 16 and has secured to its extremity within the head 18 a crank 22 pivotally connected to a driving link 24 via a pin 26. The lower extremity of the driving link 24 is formed into a hollow cylinder 28 within which is pivotally mounted a cylindrical stud 30 connected to a block 32 formed with a cylindrical hole 34 which receives a vertically mounted needle-bar 36 in sliding engagement therewith. The needle-bar 36 has a uniform cross sectional configuration for a continuous portion thereof in length exceeding the amplitude of needle-bar reciprocation. The needle-bar 36 supports a needle 38 and is journaled for endwise reciprocation in a bearing 40 mounted in the bottom section of the head 18 and a bearing sleeve 42 slidably mounted in an aperture in the roof 43 of the head 18. The sleeve 42 is held against turning movement about its axis by a screw 45 which contacts a slabbed surface (not shown) on the bearing sleeve 42. Also, mounted vertically in the head 18 for endwise movement is a presser-bar 44 that supports a presser-foot 46 on its lower extremity. It is here noted that the present invention could also be embodied in a sewing machine that utilizes an endwise reciprocable needle-bar.

Mounted in the bed 12 of the machine beneath the head 18 are the usual throat plate 48, feed dog 50, looper 52 and a loop cutting blade 54. The drive mechanism for the feed dog, looper, blade and needle-bar is timed so that the needle and feed mechanism cooperate to provide a line of cut loops in the backing material, in the usual manner.

Extending through the bed 12 and upwardly adjacent the standard 14 is a connecting rod 56 the lower end of which may be operatively connected to a foot treadle or knee lift of any other means designed to impart endwise movement to the connecting rod. The upper end of the connecting rod is pivotally connected to one extremity of a lever 58 in turn pivotally mounted intermediate its ends on the shank of a shoulder screw 60 secured to the arm 16. To the other extremity of the lever 58 there is secured a pin 62 which protrudes through a slot 64 formed in the upper extremity of a vertically disposed bar 66 and through a circular opening 68 formed in the lower extremity of a Vertically mounted link 70. The lower extremity of the vertically disposed bar 66 is secured to a leverage block 72 formed with a hollow cylindrical section 74 which slidably receives the presserbar 44. Above the hollow cylindrical section 74 there is secured to the presser-bar an apertured block 76 and mounted on the presser-bar 44 between the block 76 and the ceiling of the upper section of the head 18 is a coil spring 78 which exerts a downwardly directed pressure on the block 76. The pressure exerted by the spring is capable of being adjusted by a hollow thumb 80 threaded into the top 43 of the head 18. A hand-operated presserfoot lift lever 83 is pivotally mounted on the head 18 for operative engagement with the leverage block 72, in the usual manner.

The upper section of the vertically mounted link 70 is pivotally connected to one extremity of a horizontally disposed rock lever 82 formed with a vertical, centrally located, elongated aperture 84 and a horizontal, cylindrically shaped aperture 86 extending through the lever 82 midway between the lever ends and transversely of the length of the aperture 84. The aperture 84 receives an apertured stud 88 that extends upwardly from a rocking block 90, with which it is integrally formed. The rocking block 90 is pivotally mounted on a pin 92 secured to the head 18 The stud 88 is pivotally connected to the rock lever 82 by a pin 94 received by an aperture in the stud 88 and press fit into the hole 86 in the rock lever 82. The other extremity of the rock lever 82 is pivotally connected by a pin 91 to a U-shaped connecting bar 93 formed with a pair of parallel legs 96. Depending from the roof 43 of the head 18 is a vertically adjustable stud 95 mounted in an aperture in the roof 43 and formed at its lower end with a disc 97 that extends into the vertical path of the bar 93 thereby to place a lower limit on the vertical path along which the bar 93 may move.

The bearing sleeve 42 is formed in its upper section with a vertical slot '98, the outer surface of the midsection of the sleeve being threaded at 100 for a reason set forth below. An apertured yarn or thread guide finger 99 secured to the needle-bar 36 is received by the vertical slot 98. The sleeve 42 includes a lower extremity 102 formed with a plurality of spaced vertical slots 104 that define a plurality of tangs 105. The tangs 105 each includes a shank section 106 having a thickness less than that of the section of the sleeve 42 above the lower extremity 102. The lower end of the shank for each tang curves outwardly to form a lip 108. The lip 108 is thicker than any of the other sections of the sleeve and takes the shape of one of the halves of a frustrum which has been sectioned along its vertical axis. Slidably mounted on the sleeve 42 is a collar 110 formed in the inner surface of its lower extremity with a conical recess 112 that extends inwardly from the bottom of the collar and is adapted to engage the outer surface of the lip 108, as explained below. Also mounted on the sleeve 42, above the collar 110, is a coil spring 114 the lower end of which engages the upper end of the collar 110. Also mounted on the sleeve 42 is a cylindrical unlatching block 116 having a reduced upper section 118 whose outer surface is formed with two oppositely disposed grooves 120 which in cross section are shaped rectangularly. The grooves 120 are formed to receive the spaced parallel legs 96 of the U-shaped connecting bar in sliding engagement therewith. The unlatching block 116 is provided with an aperture 122 formed to receive the sleeve 42 and a conical recess 124 in the wall of the aperture 122 which extends inwardly from the bottom of the unlatching block. The aperture 122 is countersunk at 126 to receive the sleeve 42, spring 114 and collar 110, as best understood by viewing FIGS. 2 and 4. The sleeve 42, collar 110, spring 114 and the unlatching block 116 are held together as a unit by a nut 128. The nut 128 is mounted on the bearing sleeve 42 above the head 18, and when it is turned to threadedly engage the threaded mid section it serves to pull the shank 106, collar 110, spring 114 and block 116 upwardly toward the top 43 af the head 18. As the nut 128 is rotated clockwise, as viewed from above, the sleeve 42 is pulled upwardly, thereby forcing the lip 108 into contact with the conical recess 112 in the collar 110, which collar contacts the coil spring 114 and forces it upwardly against an inner stop ledge 130 formed in the wall of the aperture 122 of the unlatching block 116, thereby to move the block upwardly and bring the elements within the block together as a unit.

Secured to the needle-bar 36 intermediate its ends is a latching block 132 formed with a cylindrical aperture 134 which receives the needle-bar 36. The latching block 132 is formed from two

rectangular blocks

136 and 138, the smaller block 138 having for-med therein a threaded aperture that receives a screw 140. The latching block 132 is formed with a slit 142 whose sides may be moved toward or away from each other by adjusting the screw 140, thereby to tighten or loosen the block on the needlebar. Into each of two oppositely disposed sides 144 of the latching block 132 there is cut a vertical slot 146 each of which receives a latch finger 148. Each latch finger 148 is pivotally mounted intermediate its ends on a pin 150 mounted in the latching block. Each latch finger 148 is formed with an upper unlatching end section 152 formed with an outer surface 154 that bends inwardly towards the needle-bar and is adapted to engage the conical recess 124 in the unlatching block 116 when the unlatching block is actuated. Each latch finger 148 is also formed at its lower extremity into a hook 156 having a horizontal lip 158 that extends inwardly towards the needle-bar 36. The latch fingers 148 are biased by a substantially M-shaped spring 160 mounted on the large block 136 and connected at each end extremity of the spring to a respective one of the latch fingers so that the lower extremity of each latch finger is pivoted inwardly towards the needle-bar 36. Extending upwardly from and secured to the block 32 is a latch collar 162 formed with a circular flange 164 under which the horizontal lip 158 of each of the latch fingers may slip to entrain the needle-bar with the block 32, as explained below.

Turning now to the operation of the mechanisms described above, as the needle 38 moves downwardly it carries thread (not shown) down through work material (not shown) being moved over the throat plate 48 by the feed dog 50, whereupon the looper 52 intercepts the thread thereby to form a loop of the thread on the looper as the needle moves back up through the work material. The cutter 54 and looper 52 move in such a manner as to cause the severance of each loop of thread as it is formed on the looper thereby to provide the line of severed tufts desired. When the operator wishes to start a new line of tufts or for any other reason wishes to stop the reciprocation of the needle-bar but continue the operation of the looper and cutter thereby to sever any accumulated loops on the looper the operator need merely, according to the arrangement of the mechanism of the present invention, actuate the treadle or knee lift that is connected to the connecting rod 56. When this occurs the rod 56 is pulled downwardly thereby pivoting the lever 58 on the shoulder screw 60 and raising the pin 62 at the end of the lever 58 upwardly. The upward movement of the pin 62 pulls the presser-foot 46 upwardly against the bias of the spring 78 and also pushes the link 70 upwardly. Upward movement of the link 70 pivots the rock lever 82 thereby to push the U-shaped connecting bar 93 downwardly. As the bar 93 moves downwardly the legs 96, captured by the grooves 120, force the cylindrical unlatching block 116 downwardly against the bias exerted by the coil spring 114. When the block 116 reaches a predetermined point in its downward movement it is in position to be engaged by the latch fingers 148. As the block 116 is moved downwardly the needle-bar carrying the latching block 132 continues to reciprocate until the upper unlatching end sections 152 are brought into engagement with the wall of the conical recess 124 thereby to urge the sections 152 inwardly. The unlatching occurs when the needle-bar is at or very cloes to the top of its run at which point the needle-bar is stopped or moving very slowly. Thus, the fingers 148 are pivoted so that the hook end 156 of the fingers moves outwardly and the lip 158 of the fingers slides out from beneath the circular flange 164 on the latch collar 162. FIG. 4 shows the fingers in both the latched (dot-dash outline) and the unlatched (solid outline) positions. Because the drive mechanism of the tufting machine has not been disengaged by the actuation of the unlatching block 116 the crank 22 continues to move the driving block 32 and the latch collar 162 up and down over the surface of the needle-bar 44, while the needle-bar remains in a raised position, as explained below. In addition, the drive mechanism for the feed, looper and cutter continues to operate thereby to sever any loops of thread remaining on the looper, without forming any additional loops. Since the presser-foot is raised at this point the operator may move the work material in any direction over the bed of the machine to change the position of the work material relatively to the needle so that the operator may thereafter change the direction of the seam or start a new seam.

Turning now to the operation of the mechanism utilized to hold the needle-bar in a raised position, as can be seen more clearly in FIGS. 2 and 4 as the unlatching block 116 is pushed downwardly pressure is applied gradually through the coil spring 114 to the collar 110 which in turn gradually forces the tangs 105 inwardly into engagement with the needle-bar 36. The resiliency of the coil spring 114 acts to prevent undesirable wear on the needle-bar as it is being reciprocated after pressure has been applied to the tangs 105, forcing them inwardly into contact with the needle-bar, and before the latch fingers 148 are actuated. After the latch fingers 148 have been actuated and the needle-bar disengaged from the driving block 32 at the top of the needle-bar run the continued application of pressure on the needle-bar through the block 116, spring 114, collar 110 and the tangs 105 serves to hold the needle-bar in its raised position against any tendency for the needle-bar to drift downwardly.

When the operator again actuates the treadle or knee lift in order to once again entrain the needle-bar with its drive elements the unlatching block 116 is moved upwardly to its raised position thereby releasing the latch fingers 148 which pivot back to their original position. The driving block 32 meanwhile continues to be driven up and down along the needle-bar 36. When the flanges 164 is brought into engagement with the lower extremity of the latch fingers 148 the latch fingers are once again operatively connected to the latch collar 162. The present invention provides that the reengagement off the needle-bar, through the latch fingers, with the driving block 32 takes place at or near the top of the needle-bar run when the driving block is moving very slowly. Thus, the impact of the parts as they reengage is very slight preventing damage to the parts and making the engagement practically noiseless. The reengagement at or near the top of the needle-bar run is made possible by the provision of the coil spring 114. Thus, when the block 116 is lifted the needle-bar is not released immediately from the grip of the tangs because the spring 114 expands gradually after it is released from the compressing force of the block 116 thereby to release the pressure on the tangs 105 gradually so that the needle bar will not be immediately free to drift downward. The delay provided by the spring 114 is suflicient to prevent the needle-bar from drifting downwardly before the driving block 132 has time to reach the top of its vertical movement no matter where in the cycle of endwise reciprocation the driving block 132 may be when the block is lifted.

Having thus set forth the nature of this invention, what is claimed herein is:

1. A needle-bar disengaging apparatus for a machine of the class described having a frame, a needle-bar carried by said frame for endwise reciprocation relatively thereto, a needlebar reciprocating means carried in said frame, said needle-bar having a uniform cross sectional configuration for a continuous portion thereof in length exceeding the amplitude of needle-bar reciprocation, said needle-bar disengaging apparatus comprising saparable interengaging means on said needle-bar and on said needle-bar disengaging apparatus comprising separable element shiftably supported on said needle-bar and having an operative position for separating said interengaging means, means shiftably supported on said frame for movement into and out of effective position in the path of said disengaging element at a predetermined position of reciprocation of said needle-bar to urge said disengaging element into said operative position, selectively effective friction brake means carried on said frame and engageablable with said needle-bar portion of uniform cross sectional configuration, and means responsive to movement of said means shiftably supported on said frame for rendering said friction brake means eifective at least until said disengaging element is released by said means shiftably supported on said frame and said interengaging means are reengaged.

'2. A needle-bar disengaging apparatus as set forth in claim 1 wherein said means for rendering said friction brake means effective includes a coil spring operatively connecting said friction brake means to said means shiftably supported on said frame.

3. A needle-bar disengaging apparatus as set forth in claim 1 wherein said means shiftably supported on said frame includes a control block and said selectively effective friction brake means includes a resilient member operably acted upon by said control block selectively to bring said resilient member into engagement with said needle-bar.

4. A needle-bar disengaging apparatus as set forth in claim 3 including a spring operatively connected between said control block and said resilient member.

5. A needle-bar disengaging apparatus as set forth in claim 1 in which said separable interengaging means includes a pair of disengaging elements pivotally supported relatively to said needle-bar at diametrically opposite sides thereof, said disengaging elements each formed at one extremity with an inturned hook and at the opposite extremity with an operating arm and a collar connected to said needle-bar reciprocating means, said collar having formed thereon a flange, said collar being endwise slidable on said needle-bar and said annular flange being complemental to the inturned hooks on said disengaging ele- 7 ments, and in which said means shiftably supported on said frame includes a control block supported on said frame for movement coaxially of said needle-bar, said control block being formed with camming surfaces shiftable into the paths of said operating arms of said d'isengaging elements.

6. A needle-bar disengaging apparatus as set forth in claim 5 in which said friction brake means comprises a bearing sleeve for said needle-bar, a resilient member formed on said bearing sleeve, and means shiftable in response to movement of said control block to bring said resilient member into engagement with said needle-bar.

8 References Cited UNITED STATES PATENTS 3/ 1943 Bradwell 112-221 XR 5/1943 Cobble et al 112221 XR FOREIGN PATENTS 12/1966 Germany.

US. Cl. X.R.