US3444832A - Integral buttonholing mechanism - Google Patents

Description

May 20, 1969 G. l. GRAY INTEGRAL BUTTONHOLING MECHANISM Sheet of3 Filed July 31, 1967 Fig. l

E JENV T R A T S INVENTOR. GEORGE l. GRAY BY M84141 y 1969 G. GRAY I 3,444,832

INTEGRAL BUTTONHOLING MECHANISM Filed July 31, 1967 Sheet 2 of s INVENTOR. GEORGE l. GRAY BY 14,1 & (161mm May 20, 1969 G. l. GRAY INTEGRAL BUTTONHOLING MECHANISM INVENTOR. G EORGE l.

GRAY

United States Patent 3,444,832 INTEGRAL BUTTONHOLING MECHANISM George I. Gray, 962 Ednabelle Court, El Cajon, Calif. 92021 Filed July 31, 1967, Ser. No. 657,355

Int. Cl. Db 3/02, 3/06 U.S. Cl. 112-158 7 Claims ABSTRACT OF THE DISCLOSURE The buttonholing mechanism is incorporated into a conventional type of zig-zag sewing machine and controls the action of the existing forward and reverse feed and the lateral needle motion in a set sequence to operate the machine automatically through a complete buttonhole cycle, without any changes in control settings once the cycle is started. The buttonhole produced is round ended and the stitch width and spacing are constant as preset to suit the specific buttonhole, regardless of the length of the buttonhole, which is also preselected.

Background of the invention The present invention relates to sewing machines and specifically to an integral buttonholing mechanism for a zig-zag sewing machine.

Present types of buttonholing mechanisms usually involve shaped cams which control the needle motion, Often several control actions are required during the stitching of a buttonhole and the operation is not particularly simple. With a cam there are usually a specific number of stitches made in one buttonhole cycle and any change in the length of the buttonhole changes the stitch spacing. Also, the ends of the buttonhole are usually finished with wide bar tacks, which do not have the neat appearance of round ended tailor made buttonholes.

Summary of the invention The mechanism described herein is incorporated in a zig-zag sewing machine and coupled to the existing feed and zig-zag controls. Controls are provided for setting the length of the buttonhole and for setting the mechanism to the start of a buttonhole, the latter control including an indicator which shows the progress throughout the complete cycle. Stitch spacing and zig-zag width are preset on the conventional controls to suit the specific buttonhole and are not changed during the cycle, regardless of the length of the buttonhole. Round ends are formed automatically in a preset sequence by synchronization of the zig-zag action with the reversal of feed direction. When not in use the mechanism is shut off and does not interfere in any way with normal operation of the machine. The basic mechanism is compact and is adaptable to many different machines in present use.

Brief description of the drawings FIGURE 1 is a front elevation view of a typical sewing machine, showing the general installation of the buttonholing mechanism;

FIGURE 2 is an enlarged view of the buttonholing controls;

FIGURE 3 is a detail of the buttonhole stitch pattern obtained;

FIGURE 4 is an enlarged front elevation view of the buttonholing mechanism, with portions of the sewing machine indicated to show the relationship;

FIGURE 5 is a sectional view taken on line 55 of FIGURE 4;

FIGURE 6 is a sectional view taken on line 66 of FIGURE 4;

FIGURE 7 is a view similar to a portion of FIGURE 6, showing the mechanism in the oif position;

FIGURE 8 is a sectional view taken on line 88 of FIGURE 4;

FIGURE 9 is a sectional view taken on line 9-9 of FIGURE 6; and

FIGURE 10 is a sectional view taken on line 10--10 of FIGURE 5.

Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawings.

Description of the preferred embodiment The mechanism includes an actuator unit 10 driven through a gear box 12 from a suitable power take-01f 14 in the sewing machine. Actuator unit 10 operates a coupling unit 16 which is connected to the feed control lever 18 of the basic machine, the coupling unit also operating linkage 20 which leads to the zigzag control arm 22 controlling the needle bar 24.

In FIGURE 1, this mechanism is shown in a typical sewing machine 26, the actuator unit 10 being installed in the lower portion of the standard 28 and driven by a shaft which constitutes the power take-off 14 in the base 30. Coupling unit 16 is mounted above the actuator unit 10 alongside the feed direction control lever 18, which swings vertically and linkage 20 extends through the casing arm 32 of the machine to the zig-zag control arm 22. This arrangement is suitable for one type of machine chosen for illustration and there may be considerable variation in the location and interconnection of the main portions of the mechanism to suit other machines. For the purpose of the following description only those portins of the machine pertinent to the buttonholing mechanism are shown and the frame structure of the machine is indicated in broken line in certain figures to show the relationship of the parts. It is assumed that the various units will be attached to the machine frame in a suitable manner, depending on the frame structure and accessibility.

Actuator unit 10 is contained in a box-like frame 34 having a back panel 36, a top wall 38 and a bottom wall 40, the sides preferably being closed for rigidity as shown. A drive shaft 42 extends downwardly through bottom wall 40 to the gear box 12 and carries a bevel gear 44 which engages a bevel gear 46 on power take-off shaft 14. On the upper end of drive shaft 42 is a bevel gear 48 which engages a bevel gear 50 on a cam shaft 52 extending through back panel 36. At the rear of back panel 36 is a rocker plate 54 hinged at its upper end on a vhinge pin 56 to swing parallel to the back panel, said rocker plate having an elongated slot 58 through which cam shaft 52 passes. Rocker plate 54 has rearwardly projecting side flanges 60, between Which is a slidable cam follower 62 having forwardly projecting upper and lower flanges 64. On the rear end of cam shaft 52 is an eccentric cam 66, which engages flanges 64 and oscillates the cam follower 62 generally vetrically as the cam rotates.

Fixed behind back panel 36 is a sub frame 68 having a back plate 70 spaced from and parallel to said back panel. Rotatably mounted in the back plate 70, substantially coaxial with cam shaft 52, is a setting wheel 72 having a toothed gear portion 74 behind the back plate and being retained by a split ring 76, or similar means, forward of the back plate. The forward face of setting wheel 72 has a diametrical slot 78 and riding slidably in the slot is a shoe 80 pivotally mounted on cam follower 62. By turning setting wheel 72 so that the slot 78 is inclined to the vertical, a lateral motion will be imparted to cam follower 62 as it oscillates, due to the shoe 80 sliding in the inclined slot. This in turn causes a rocking motion of rocker plate 54 about hinge pin 56.

Between rocker plate 54 and back panel 36, above the cam shaft 52, is a clutch disc 82 carried on a shaft 84 which extends forwardly through the back panel. Fixed on rocker plate 54 above the clutch disc 82 is a clutch plate 86 having a ramp socket 88, in which a clutch element 90 is held in contact with the edge of the clutch disc. In one direction of motion of the rocker plate 54, clutch element 90 is jammed between the clutch disc 82 and ramp socket 88 and imparts a slight rotary motion to the clutch disc. On the return motion the clutch element slips, the mechanism being well known and the specific details being variable. The elfect is that of a one-way ratchet drive, but with no fixed increment of rotation, the amount of rotation at each oscillation depending on the swing of the rocker plate 54, which is controlled by setting wheel 72.

Fixed on shaft 84 forward of back panel 36 is a pinion 92, which engages a further pinion 94 spaced laterally therefrom and mounted on a shaft 96 journalled in the back panel. Shaft 96 carries an eccentric sequencing cam 98 which engages the vertically spaced flanges 100 of a slide plate 102, vertically slidably mounted on back panel 36, the cam being shaped to move the slide plate rapidly at each 180 degrees of revolution of the cam, with little motion therebetween. Adjustably secured to slide plate 102 is a tie plate 104, from which a connecting rod 106 extends upwardly through top wall 38.

Extending concentrically through shaft 96 is an inner shaft 108, on the forward end of which is a large gear 110, the rear end of said inner shaft projecting through back plate 70 and carrying a small gear 112. On back plate 70 is a compound reduction gear 114 connecting small gear 112 to gear portion 74 of the setting wheel 72, to provide a large reduction drive thereto. On the forward portion of shaft 84 is a rotatable sleeve 116 carrying a gear 118 which engages gear 110, so that rotation of said sleeve will turn setting wheel 72. Sleeve 116 projects from the front of the sewing machine and is fitted with a length setting knob 120, while shaft 84 extends further and is fitted with an indicating knob 122, as in FIGURE 6.

Coupling unit 16 includes a bracket 124 having a gen- 7 erally vertical side plate 126 extending into the machine.

Feed control lever 18 is provided with an actuating pin 127 projecting laterally across bracket 124, the side plate 126 having an arcuate cut out 128 to clear the pin as the lever is raised and lowered between forward and reverse feed positions. On side plate 126 is a hinge plate 130 pivoted at its lower end on a hinge pin 132 to swing parallel to the side plate. At the upper end of hinge plate 130 is a tongue 134 which holds one end of a compression spring 136, the other end of the spring being held in a retainer 137 on side plate 126. The spring biases hinge plate 130 inwardly into the machine, the inner edge having an arcuate cut out 138 to clear pin 127, similar to cut out 128 and the motion of the hinge plate being limited by a stop 139 on the inner edge of side plate 126. At the lower end of hinge plate 130 is an actuating bar 140 held by screws 142 through elongated slots 144 in the bar, which allow the actuating bar to slide generally vertically. The inner edge of actuating bar 140 has a notch 146 to receive pin 127 when the hinge plate 130 is held inwardly by spring 136, as in FIGURE 6. At the lower end of actuating bar 140 is a lug 148, the upper end of connecting rod 106 having a laterally turned arm 150 which is pivotally inserted through the lug generally coaxial with hinge pin 132.

On inner shaft 108 within sub frame 68 is a lock out cam 152 which, in one position, engages and lifts a push rod 154 extending slidably upwardly through the top of the sub frame. The upper end of push rod 154 is pivotally connected to an arm 156 extending inwardly from the lower end of hinge plate 130. When push rod 154 is lifted, the hinge plate 130 is tilted about hinge pin 132, compressing spring 136 and moving the actuating bar 140 out of engagement with pin 127. In this, the locked out position shown in FIGURE 7, lever 18 is free to operate normally.

The zig-zag control arm 22 moves the needle bar 24 to shift the needle from one side to the other of the sewing foot, as indicated in the two positions in FIGURE 4, and also controls the width of the zigzag stitch. Usually the motion in controlled by some type of cam, either directly or by coupling mechanisms. Since the mechanism can vary considerably the linkage 20 is shown somewhat schematically and terminates in a bellcrank 158 pivotally mounted on the machine adjacent coupling unit 16. An arm 160 of bellcrank 158 rests on a flange 162 on the upper end of actuating bar 140, so that the needle is moved from one side to the other as the direction of feed is reversed. Normally the control arm 22 is biased for self return, but it would be a simple matter to make a push-pull connection between actuating bar 140 and bellcrank 158, if needed. In some types of machines it may be more practical to use push-pull cables instead of pivoted linkage.

Since it is unnecessary for the actuator unit 10 to operate when the buttonholing mechanism is not in use, means is provided to disconnect the unit from the machine drive. One means for accomplishing this is shown in FIGURE 4, wherein bevel gear 44 is attached to a clutch rod 164 extending through shaft 42 and is coupled to the shaft by a spline 166. Bevel gear 44 is biased into engagement with bevel gear 46 by a compression spring 168 in gear box 12 and is declutched by forcing the gear down against the spring. The upper end of clutch rod 164 projects above bevel gear 48 and is fitted with a bevelled cap 170. Fixed on sleeve 116 is a declutching cam 172 which, in one position, engages cap and pushes clutch rod 164 down to declutch the drive means.

Setting knob 120 has a marker 174 which is aligned against a scale 176 marked in suitable increments on the machine to indicate length of buttonhole. In the OFF position the alignment of the mechanism is such that declutching cam 172 is holding bevel gear 44 out of driving engagement, as in the broken line position in FIGURE 4, and lock out cam 152 is holding push rod 154 up, as in broken line position in FIGURE 9, to disengage the coupling unit 16. A stop 178 can be provided in frame 34 to stop the motion of declutching cam 172 in tthe declutched position, so limiting rotation of the setting knob 120 to one direction and preventing overtravel of the cams. As soon as setting knob 120 is turned from the OFF position both cams 152 and 172 are released, putting the buttonholing mechanism into operation.

A typical buttonhole stitch pattern is shown in FIG- URE 3 and can be made of any length without variation in stitch spacing. To make a buttonhole the conventional controls of the machine are adjusted to set the zig-zag for width of stitch and the feed for stitch spacing. These need not be changed throughout the operation, unless specifically required for special stitching, such as for a decorative effect, as in corded buttonholes. Indicator knob 122 is set with its pointer 180 on the marker 174 of setting knob 120, with the setting knob at off position, putting the actuator unit 10 at the start of a cycle. Setting knob 120 is then turned to the position on scale 176 representing the length of buttonhole required. This action, through gears 118, 110, 112, 114 and 74, turns setting wheel 72 to incline slot 78 to the appropriate angle. The oflset of setting wheel 72 controls the amount of rotation of clutch disc 82 at each oscillation, and so controls the rate at which the mechanism advances through a complete cycle. This, in effect, determines the number of stitches made during one cycle which, since the stitch spacing or feed is not changed, controls the actual length of the buttonhole. Thus a small offset of the setting wheel causes a small oscillation of the rocker plate 54 and the clutch disc 82 is advanced in small increments, requiring a relatively long time to complete a revolution and allowing the machine to complete a large number of stitches. The greater the offset of the setting wheel, the faster the clutch disc will rotate and the less the number of stitches the machine will 'be able to complete in one cycle of the mechanism.

When the machine is operated, the clutch disc 82 is turned at the set rate, turning pinion 92 which turns pinion 94. When the stitching nears the end of one side 182 of the buttohole, as in FIGURE 3, sequencing cam 98 raises slide plate 102 and pushes up on connecting rod 106, causing actuating bar 140 to lift and move feed control lever 18 to the reverse position, as moving from the full line to the broken line position in FIGURE 6. While this feed reversal is taking place the linkage 20 is also operating to move arm 22v and shift the needle across to the other side of its working area. Since the stitch Width is unchanged the stitching Will continue across as the feed direction changes, resulting in the round end 184 in FIGURE 3. Cam 98 and linkage 20 are designed to provide the correct ratios of motion to ensure a proper round end, the specific design depending on the machine and the motions of its existing mechanism. Most buttonholing mechanisms at this point produce full width bar tacks which often pile up as the feed reverses and do not have the neat appearance of the round end. However, by proper cam shaping the buttonhole could be made square ended if necessary. Stitching then continues along the second side 186 of the buttonhole until the feed is again reversed, causing the final round end 188 to be formed. No control adjustments are needed throughout the operation, all necessary actions in the sequence being controlled by cam 98.

Indicator knob 122 turns with clutch disc 82 and pinion 92 and shows the position of the mechanism in the cycle at all times, so that it is easy to see when the ends are about to be formed. This facilitates handling and alignment of the material on the machine. Pointer 180 also allows the mechanism to be set to the correct starting position for each buttonhole and ensures consistently accurate placement of buttonholes on the material. When buttonholing is complete, the setting knob 120 is returned to the OFF position, so that cams 152 and 172 lock the mechanism out of operation, allowing the anachine to be used in a normal manner.

It is understood that minor variation from the form of the invention disclosed herein may be made Without departure from the spirit and scope of the invention, and that the specification and drawings are to be considered as merely illustrative rather than limiting.

I claim:

1. In a sewing machine having drive means, zig-zag means including a control arm for shifting the needle from side to side, and feed direction reversing means, the improvement comprising:

an integral buttonholing mechanism mounted in the machine and including an actuator unit connected to and driven by said drive means;

actuating means in said actuator unit coupled to said control arm and said feed reversing means to shift the needle and reverse the feed simultaneously;

a coupling unit having an actuating bar slidably mounted thereon with means for connection to said feed direction reversing means;

said actuating means having a push-pull driving connection with said actuating bar;

and variable speed control means in said actuating means to vary the speed thereof relative to the operator-controlled speed of the drive means.

2. The structure of claim 1 and including linkage means connected between said actuating bar and said zig-zag control arm.

3. The structure of claim .1, wherein a portion of said coupling unit, on which said actuating bar is mounted, is hinged;

and lock out means connected to said hinged portion to move said actuating bar into and out of engagement with said feed direction reversing means and said linkage.

4. The structure of claim 3 and including means for efiectively disconnecting said actuator unit from said drive means.

5. The structure of claim 4, wherein said means for disconnecting includes clutch means between said drive means and said actuator unit, and declutching means operable to disconnect the actuator unit from the drive means.

6. The structure of claim 5 and including a setting control connected to said speed control means, said setting control having an OFF position;

and means actuated by said setting control in the OFF position to operate said lock out means.

7. The structure of claim 6 and including further means actuated by said setting control in the OFF position to operate said declutching means.

References Cited UNITED STATES PATENTS 5/1963 Hayashi et al. 112-158 2/1967 Szostak 1'1265 X US. Cl. X.R. 112-65

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