US3092055A - Means responsive to sewing-machine presser-foot operation for workcontrol positioning of needle bar - Google Patents

Description

June 4, 1963 R. H. HALL 3,092,055

MEANS RESPONSIVE 'ro SEWING-MACHINE PRESSER-FOOT OPERATION FOR WORK-CONTROL POSITIONING OF NEEDLE BAR Filed Sept. 17, 1956 3 Sheets-Sheet 1 INVENTOR: @0/090 75. W444 June 4, 1963 R. H. HALL 3,092,055

MEANS RESPONSIVE T0 SEWING-MACHINE PRESSER-F'OOT OPERATION FOR WORK-CONTROL POSITIONING OF NEEDLE BAR Filed Sept. 17, 1956 3 Sheets-Sheet 2 INVENTOR. Era/m) 77 #041 W BYWWQM June 4, 1963 R. H. HALL 055 SEWING-MACHINE PRES MEANS RESPONSIVE T SER-FOOT OPERATION FOR WORK- TROL. POSITIONING OF NEEDLE A Filed Sept. 17, 1956 3 eets-Sheet 3 1N VENTORZ EMA 0E0 ff WALL United States Patent F 3,092,055 MEANS RESPONSIVE TO SEWING-MACHINE PRESSER-FGOT OPERATION FOR WORK- CONTROL POSITIONING 0F NEEDLE BAR Richard H. Hall, 3907 Estes Road, Nashville, Tenn. Filed Sept. 17, 1956, Ser. No. 610,362 7 Claims. (Cl. 112-221) This invention relates to means responsive to sewingmachine presser-foot operation for work-control positioning of needle bar.

More particularly the invention pertains to simple mechanical means responsive to presser-foot-elevating mechanism for selectively raising, or lowering, the needle bar for removal, or needle pivoting, of -a work piece, said means comprising: (1) a pair of cams mounted on the hook-rotating shaft and 180 out of phase, a cam-operating roller between said cams and selectively movable to engage either one thereof to rotate said shaft for raising or lowering the needle bar thru conventional synchronized mechanism, a knee-engageable operator laterally movable in two directions to elevate the presser foot, means connecting said operator to said cam-operating roller, and interlock mechanism for preventing movement of said roller except when the needle-bar-driving mechanism is disconnected from the conventional pedalcontrolled powering and braking unit, or (2) a plate pivoted to the machine head and having a notch there in straddling a pin on the needle bar, said gap being wide enough so as not to engage said pin during a sewing operation, and p-resser-foot-connected link means selectively connectable to said plate on opposite sides of the pivot point, whereby raising of said presser foot will tend to raise (or lower) the needle bar, as desired.

It is the principal object of the invention to provide simple, economical, yet highly effective mechanical means for positioning a sewing-machine needle bar as desired at the end of each sewing step.

It is a further object to provide such a device with protective mechanism for preventing operation except when the machine proper is disconnected from the motor and the brake.

It is the overall object to generally improve the design and efficiency of mechanical needle positioners.

In the drawings:

FIG. 1 is a perspective view partly broken away of a preferred embodiment of the invention.

FIG. 2 is a front elevational view of the under-table structure for operating and controlling the mechanism of FIG. 1.

FIG. 3 is an end elevational view of a modified form of the invention.

FIG. 4 is a pictorial view of a further embodiment of the invention.

With reference now to FIGS. 1 and 2 of the drawings, the numeral '11 generally designates a sewing machine superstructure which comprises: a base plate 13' adapted to seat in conventional manner in a central aperture in a sewing machine table top (not shown), a goose-neck casing rising upwardly from one end of base 13 and extending laterally thereover and carrying on its free end the housing 17 for the needle bar 19 and the presser-foot bar 21. The needle bar 19 and the wheel W are driven by motor M thru conventional mechanism (not shown). Presser-foot bar 21 raises and lowers the presser foot 22 in response to rocking movement of the lever 23, to the far end of which it is connected by the arm 24 by link 25. The other end of the lever 23 is connected by link 26 to the rocker arm 27 at its near end. The far end of rocker arm 27 is provided with a cylindrical cam follower 28 which engages the Y-shaped cam 29 by Patented June 4, 1963 2 which it is lifted from its presser-foot lowering position shown in the drawing to an elevated presser-foot-raising position by movement of said Y-shaped cam either clockwise or counter-clockwise from its disclosed position.

Cam 29 is mounted on an arm 30 adjustably held by the block 31. Block 3 1 is rigidly connected to the rotatable shaft 32. Shaft 32 is mounted beneath the base plate 13 by suitable bearings (not shown). Shaft 32 has extending downwardly therefrom a bifurcated shaftrotating device 33 the forked elements 33a of which are adapted to engage the inner and outer surfaces of the thigh of the operator just above the knee. T ines 33a are desirably but optionally provided with cushioning pads 33b.

The motor M also drives (thru conventional mechanism, not shown) the hook shaft 35. The hook shaft 35 and the needle bar 19 are driven in co-ordination by the motor M thru mechanism including a clutch and a brake (both not shown) constructed and mounted as a unit with the motor M and controlled by the lever 37. Lever 37 is moved downwardly by toe pressure on the pedal 39, which causes a pull on a connecting rod the upper and lower elements 41 and 42 of which are adjustably connected by the coupler 43. Heel pressure on the pedal 39 causes an upward swinging of the control lever 37 for application of the built-in brake for stopping the machine.

In the showing of FIG. 2 the lever 37 is in its intermediate position in which both the brake and the clutch are released so that the machine elements can be easily turned by the herein disclosed mechanism (or manually thru wheel W) for positioning the needle bar 19 in down or up position, as desired, for rotating or removing the work. In this free position of the machine elements a pin 45 on the clutch and brake-operating arm 37 is in position to enter an arcuate slot 46 in the plate-type rocker arm 47 which is pivoted at 48 to the motor-supporting bracket 4-9. The rocker arm 47 is rotated, so as to engage over the pin 45, by the connecting rod 50 and the crank arm 51 fixed to the knee-rotated shaft 32. This shaft 32, it should be noted, cannot be rotated, due to the stopping action of the pin 45, when the control lever 37 is in either braking or driving position which places the pin 45 out of alinement with the slot 46 Thus the presser foot 22 can be raised only when the machine elements are in free wheeling conditions.

The essence of the present invention lies in the provision of means for positively positioning the needle in either up or down position in response to movement of the presser foot upwardly to release the work for either its removal or its rotation about the depressed needle, or in response to movement of mechanism for so moving the presser foot. In the species of FIGS. 1 and 2 such co-ordinated movement of the needle bar is effected by a pair of cams 53 and 54 formed of two mating halves and clamped around the shaft 35 by the integral connecting devices generally designated 55. The cams 53 and 54 have beveled faces coming to relatively sharp points at 56. The beveled faces of the cams 53 and 54 are positioned out of phase and the points 56 are spaced apart sufficiently to receive therebetween the cam-moving roller 57.

Cam-moving roller 57 is low-frictionally mounted on the pin 58 (as by ball or roller bearings). Pin 58 is carried by a slide member 59 having a guide channel fitting over the shaft 60, which forms a part of the conventionally constructed sewing machine. Slide 59 has rigidly attached thereto the forwardly and horizontally disposed flat bar 61 which is guidedly received in a slot 62 in the guide block 63-. Block 63 is fastened to the base of the machine by any suitable means such as the bolt 64.

The roller 57 is moved longitudinally of the shaft 35 (so as to engage one of the two cams 53 and 54 for rotation of said shaft) by the bifurcated arm 65', the tines 66 of which engage on opposite sides of the plate 61. Arm 65 is rigidly fixed to the knee-rotatable shaft 32. The cams 53 and d are positioned on the hook-rotating shaft 35 in such positions that in the raised condition of the needle bar the thread-feed-controlling takeup and tensioner (not shown) will be in optimal positions for removal of work and for minimizing danger of unthreading the needle at beginning of the next sewing operation.

In operation, the knee-gripping member 33 is locked against movement by the rocker arm =47 and the pin 45 When-ever the control lever 37 is in running or braking positions which locate stop pin 45 out of alinement with the slot 46. This prevents any damage to the cams or the other mechanism which could result from trying to lift the presser foot or move the needle bar while the mechanism is running or the brake is applied. When the arm 37 is in the free position shown in the drawing, the knee-operated member 33 can be swung to the right or to the left. Movement to the left, with the connection shown, will cause both a lifting of the presser foot and a lowering of the needle bar, if not already lowered. Conversely, movement to the right will raise the needle bar, if not already raised, and simultaneously raise the presser foot 22.

in the species of FIG. 3 the housing 71 for supporting and guiding the needle bar and presser-foot shaft is shown with its cover plate removed to reveal the needle bar 72 and the presser-foot shaft 73, the latter being urged to its lowered position by the surrounding coil spring 74. Spring 74 engages against a bushing 75 rigidly attached to the shaft 73. Bushing 75 has an extension 76 for engagement with, and operation by, conventional mecha nism (not shown) by which the presser foot 73" is raised and lowered in known manner. The mechanism by which the needle bar 72, and thereby the needle 72', is selectively raised or lowered in response to raising the presser foot 73', comprises a bifurcated member 77 pivoted at 78 on the supporting cross-member 79. A link 80 connects the bushing 75 on the presser foot to the bifurcated member 77 to rock the same about the pivot point 78 so that one of the tines 77a and 7712 will engage the pin 81 on the needle bar 72, to move the latter up and down as desired. In the full-line position of the link 80-, raising the presser foot will cause the needle bar to be raised also. When the link 89 is in the phantom-line-shown position, upward movement of the presser foot will cause the member 77 to rotate clockwise about the pin 78, thus causing tine 77b to engage pin 81 to force the needle bar 72 downwardly. The wing nut 82 is illustrative of adjustable means by which the upper end of the link 30 may be connected to the member 77 at either end of the arcuate slot 770 therein.

In the species of FIG. 4 a support bracket 83 is attached to the base B of the sewing machine M as by screws 83a and the mounting block B. Bracket 83 has pivotally attached to its upper end the U-shaped rocker member 84 pivoted thereto by the pin Me. Member 84 is apertured at 84-1; to receive the conventional presser-foot operating lever 35 which is controlled by the connecting rod 85a connected with the conventional knee-operated mechanism of the machine. Bracket 83 also rigidly supports the guide rod 36 fixed thereto by the screws 86a. Bar 86 has adjustably fastened to its near end a sleeve 86d carrying a tab 86b for mounting a pivot pin 860. Pin 86c pivotally supports the bent lever 87. Lever 87 is rocked about pin this by the member 84, to which it is connected by the bar 88, pin 38a and pin 38b adjustably received in the slot 87a. Bent lever 87 has a pair of posts 87b apertured at their upper ends to receive the pins 8% carried by the sleeve 89. Sleeve 89 is axially supported and guided at its near end on the shaft 90 which is an axial extension of the needle-bar-operating crank shaft 9:1. Shaft 90 is bored to receive and is telescoped over the near end of shaft 91, and it is fixed thereto by set screw 91a. The hand wheel W is removed and rebored to fit over the shaft 90.

A bias-cut sleeve cam 92 is snugly but low-frictionally received within the enlarged bore 89a of the sleeve 33 and is fixed to the shaft by the set screw 92b. Sleeve cam 92 also guides the far end of the sleeve 89. Sleeve 89 has mounted in bore 8% a low-friction roller 93 which engages the cam 92, as the sleeve 89 is moved co-axially thereover, to rotate the cam 92 and thereby the needlebar-operating crank shaft 91 in response to operation of the presser-foot-lifting mechanism 85 and 85a. Sleeve 89 is held against rotation by the lever -87 which optionally may also be assisted by the torque arm 94 welded or otherwise fixed to the sleeve 89. Arm 94 (if used) is slidably coupled to guide rod 86 by a sleeve 95 fixed to the end of said arm 94.

The cam 92 has a relatively sharp point 92a so as to minimize the chance of the roller 93 engaging it on dead center. The mechanism, depending upon the rotational position in which the cam 92 is fixed to shaft 90, will move the needle bar to its up work-freeing position or its down work-pivoting or holding position, as desired. It should be noted, however, that by lengthening sleeve 89, two out-of-phase cams could be used along with structure similar to the selectively operable means of FIGS. 1 and 2, so that the operator could be moving the knee to the right or left position the needle up or down as desired.

It should also be noted that this camming mechanism could be alternatively located within the housing structure generally designated M or between the hand wheel and said structure, and the cam could be a tilted disk engageable on opposite sides thereof by separate selectively movable rollers for up or down positioning of the needle bar.

While I have shown certain preferred embodiments of my invention it is to be understood that many changes can be made in the size, shape, composition and arrangement of the parts without departing from the spirit of .the invention as defined by the subjoined claims.

Having thus described my invention, I claim:

1. Means for positioning the needle bar and thereby the needle of a sewing machine selectively in up workfreeing position or in down work-holding or pivoting position, comprising: first means connectable to presser-footoperating mechanism, second means connectable to the needle-reciprocating mechanism, and third means connectcd to and operable by said first means and movable thereby from normal inoperative position in one direction into engagement with said second means to move the needle 'bar to an up position and in an opposite direction into engagement with said second means to move the needle bar to a down position.

2. Structure according to claim 1, said first means comprising a lever designed for selective knee operation in two directions for lifting the presser foot, at least one cam operator connected thereto, means for guiding said cam operator substantially parallel to a needle-bar-connected rotating shaft of said machine, and beveled-faced cam means fixed to said rotating shaft for rotation thereof by said cam operator for selectively positioning the needle bar as desired.

3. Structure accordi-ngto claim 2, and additionally comprising means for locking said lever against cam-operating movement except when the needle-bar is disconnected from both its motive power and its stopping brake.

4. Structure according to claim 3, said needle-bar connected shaft being the hook shaft of said machine, and

said knee-operated lever being movable in two directions for up or down needle-bar positioning.

5. Structure according to claim 1 wherein the first means comprises a member selectively operable in a first direction to raise the presser foot and move the needle bar to its up position and in a second direction to raise the presser foot and move the needle bar to its down position.

6. Structure according to claim 5 wherein said second means comprises a pair of cam members each having bias cut camming surfaces that are spaced apart and face each other, and said third means comprises a cam follower member positioned between said camming surfaces to normally not engage either camming surface but movable in opposite directions by said first means.

7. Structure as defined in claim 1 further containing a motor speed control and brake member, and means connected to said first means and engageable with said speed control and brake member for preventing movement of said first means when driving or braking power is applied to the needle reciprocating mechanism.

References (Iited in the file of this patent UNITED STATES PATENTS Germany Apr. 11, 1929

Claims (1)

1. MEANS FOR POSITIONING THE NEEDLE BAR AND THEREBY THE NEEDLE OF A SEWING MACHINE SELECTIVELY IN UP WORKFREEING POSITION OR IN DOWN WORK-HOLDING OR PIVOTING POSITION, COMPRISING: FIRST MEANS CONNECTABLE TO PRESSER-FOOTOPERATING MECHANISM, SECOND MEANS CONNECTABLE TO THE NEEDLE-RECIPROCATING MECHANISM, AND THIRD MEANS CONNECTED TO AND OPERABLE BY SAID FIRST MEANS AND MOVABLE THEREBY FROM NORMAL INOPERATIVE POSITION IN ONE DIRECTION

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