US1457742A - Buttonhole machine - Google Patents

Description

June 1923.

, Y 1,457,742 H. C. MILLER BUTTONHOLE MACHINE Filed Sept. 15. 1917 5 Sheets-Sheet l June 5, 1923. 7 1,457,742 H. c. MILLER BUTTONHOLE MACHINE Filed Sept. 15.1917 1 5 Sheets-Sheef 2 v 61 61. g q QMQ .n \NN"\ June 5, 1923.

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June'5, 1923. 1,457,742

. H. C. MILLER BUTTONHOLE MACHINE Filed Sept. 15. 1917 5 Sheets-Sheet 5 3n0e1o Patented June 5, 1923,.

N TE 's'r HENRY C. MILLER, 01? WATERFORD, NEW YORK.

BfiT'J-ONHOLE MACHINE.

To all whom it may concern:

Be it known that I, HENRY C. MILLER, a citizen of the United States of America, residing at WVaterford, in the county of Saratoga and State of New York, have invented certain new and useful Improvements in Buttonhole Machines, of which the following is a specification.

This invention relates to improvements in buttonhole machines, and more particularly to the means for supplying the needle thread more freely from the supply than is possible with present machines, and safety means for protecting the delicate mechanism against damage when the machine is not operating properly.

With present buttonhole machines the needle thread, which is often defective, is drawn thru the tension devices from the supply which is not always as free as it should be, with the result that the thread frequently breaks, and results in the production of damaged work. When the operator lifts the work clamp and removes the collar, it is difiicult, and in many instances, impossible, to again gage the collar and repair the buttonhole stitches with any degree of satisfaction. One of the objects of this invention is to provide means for pulling suflicient thread from the supply at the time of release of the tension to form the barring stitches, to form the purl stitches, which relieves the strain on the thread and affords a degree of safety against damaged work.

A further object of the'invention is to provide mechanism controlled by, the tension of the needle thread for preventing the raising of the work clamp if the thread should break, or become unsually slack, or in case of loose or skipped stitches, which will prevent the operator raisin the clamp. By this means the usual cycle of operation of forming a buttonhole can be performed, but the work clamp cannot be ,lifted which serves as. a warning to the operator that something is wrong. If the thread is broken the needle is rethreaded, or if the stitches have skipped, the proper. adjustments are made, or the tension is regulated, then the buttonhole is restitched without having removed the collar from under the clamp.

Another object of this invention is to provide safety means for preventing damage to the cutter blade and associated parts, if for an reason the blade sticks, or the stop mechamsm .fails to stop at the predetermined point of rest. With this means the operator is prevented from starting'the mecha-- nism until the cutting blade or other elements have assumed normal position.

Primarily the object of the invention is to provide mechanism for preventing inexperienced or careless operators damaging the parts, and at the same time preclude the possibility of removing a collar from below the work clamp when the needle or bobbin thread runs out or breaks, which will subsequently allow the o erator to mend the buttonhole, or restitc the edges thereof while the collar is in gaged and clamped position.

The invention also comprehends improvements in the detailsof construction and arrangement of parts which will be hereinafter described and particularly pointed out in the claims.

In the accompanying drawings Figure 1 is a perspective view of a Singer buttonhole machine, illustrating the application of my invention.

Fig. 2 is a side elevation of the same.

Fig. 3 is a conventional horizontal section Serial No. 214,654, filed .Jan. 31, 1918, I

have illustrated a loader and de icted conventionally the .buttonhole macliine about to be described. In the application referred to it may be readily seen how the various elements in the present case are of practical and commercial I advantage, but it is not deemed necessary here to show and describe the general application of the invention, as the subjct matter relates to improvements in the button hole' mechanism per se.

The numeral 1 indicates a base, supporting a head 2, on which is mounted a needle bar 3, tension device 4, stop mechanism 5, fast and loose pulleys 6 6*, and a work clamp 7 and below the base of the machine is ,a bobbin to cooperate with the needle in the stitching operation. Rotating with the fast pulley is a cam .8, provided with a notch 9,

in. which a spring locating pin 10 engages when the parts are at rest. The pin 10, slides in a frame 11, pivoted at 13, and from the upper end of this frame extends an arm 12, carrying a belt guide 13. Projecting from the opposite side of the frame 11, is an arm 13, and pivoted thereto is a rod 14, which projects through an opening in the base and is connected to the automatic timing mechanism (not shown) to actuate the parts after a predetermined cycle of operation has been completed.

Located on one side the head is a shaft 16, provided on one end with a lever 17 which is normally pulled down by a spring 17*, and which carries a sprin actuated pin 18, which engages the flange edge of a member 19, attachedto the pin 10. On the opposite end of this shaft is secured an arm 18, which releases the upper thread trimming mechanism 19 Loosely mounted on the shaft is a lever 20, provided on one edge with a cam 21. This lever extends through a slot in the base and engages the slotted end of a lever 22. The opposite end of the lever 22 engages a pin 22 on a slide 22", which carries a lower thread trimming blade 22.

All the above mentioned parts are old in the art are but conventionally shown for the purpose of illustrating the application of my invention.

Mounted-in bearings 26, on the base, is a transverse shaft 27, on one end of which is a handle 28, and on the opposite end is a lever 29, extending in opposite directions from the shaft. On the shaft 27, adjacent the lever 29, is a bifurcated arm 30, and in the bifurcated end is mounted a roller 31, which is located over the tail piece 32, of the work clamp 7. Extending laterally from the arm 30, are cars between which is mounted a roller 33, disposed to act on the cam 21, on the lever 20, when the shaft 27' is rocked. Fixedly secured to a lug 34, on the arm 30, is a latch lever 34*, the free end of which is disposed to be in the path of the nose 35, of a stop or catch 36, secured to the shaft 16.

Pivoted to the side of the head 2, at 37, is a lever 38, one end of which is formed with an opening 39, and through this opening extends a rod 40, pivoted at'its lower end to the latch lever 34. On the rod 40, is adjustably secured a collar 41, the end of the lever being drawn into contact with the collar by' a spring 42. The opposite end of the lever 38, is beveled and is guided in a bracket 43, fastened to the side of the head. Cooperating with the beveled end of the lever 38, is a trip 44, formed with an abutment 45, designed to be brought into the path of the end of the lever 38, in the operation of the machine, as will appear later on. The trip 44, is pivoted at 46, to the bracket 43, and extending from the pivot is a wire 47, bent at right angles, at 48, and then bent outwardly, to form a controlling device which is located in the path of the needle thread a, at a point near the needle. A spring 49, is connected to a pin extending from the lower end of the trip and is connected at its upper end to the bracket 43, which tends to rock said trip to position the abutment in the path of the end of the lever 38, when the thread breaks or becomes slack.

Mounted on a vertical pivot 51, is a latch lever 52, the free end of which is normally disposed out of the path of movement of a lug or screw 53, extending from the upper end of the arm 12, of the stop motion device, as shown in Figure 1. Secured on the lever 17, is a trip 54, the upper end of which lies behind a lug on the latch lever 52, a spring 55, attached to said latch lever serving to holdsame in contact with the trip.

Secured to the shaft 27, is a finger 56,

which lies in the path of a lug 57, fastened to the rod 14, to rock the frame 11, to start the stitching mechanism.

In the top of the head of the usual Singer buttonhole machine is mechanism for automatically controlling the lateral throw of the needle bar, and the thread at or about the time of making theend barring stitches, such for instance as that shown in Patent No. 806231, dated'Dec. 5/05, and I utilize this mechanism to actuate a thread pull-off device to supply sufficient thread to properly form the purl stitches with as little tension or drag on the thread as possible. As the details of the barring mechanism are old in the art, I have not deemed it necessary to specifically show the parts, except tlfipse directly employed to operate the pull- 0 60, indicates a lever pivoted at 61, to the top of the arm of the head, one end of said lever being in the path of a lug 62, which is actuated twice during the formation of a button-hole, when causing the formation of the barring stitches at each end. The lever 60, and the lug 62, form part of the automatic mechanism shown in the patent above mentioned. The opposite end of lever 60, is provided with a lug 63, which engages the edgeof a thread pull-off lever 64, pivoted on the post 65, which carries the usual tension disks 66. The outer end of the pulloff lever is provided with an eye 67, and to the opposite end is attached one end of a spring 68, to normally pull the lever into contact with the lug 63. Adjacent the end of the lever 64, is a vertical plate 70, the sides of which taper upwardly and its top is rounded and bent over and is formed at its upper end with a thread opening 71. The bottom of the plate 70, is bent to form a base which is formed with a slot 72, and

thru same extends a stud 73. Supported on the stud 73 is a thread check device 74, and adjacent same is a thread opening 75, formed in the plate 70.

The needle thread a, comes from the supply, and is passed thru the opening 71, then around the tension device 74, thence thru the opening 75, to and thru the eye 67 in the pull-off lever 64. From this eye the thread is passed thru a guide 76, extending from the plate 70, and thence passes thru one of a pair of eyes 77, supported on the top of the head, around the tension disks 66, thru the other of the eyes 77 to the end of the machine. The thread is then passed around the tension device 4, to the take-up lever, and is then passed over asuitable guide, over the controller wire 48 to and thru the needle.

In operation, the operator, thru suitable connections not shown,'rocks the shaft 27, by pulling on the upper end of the lever 29, which movement causes roller 33 to contact with the cam 21 which rocks the lever 20, and thru the connections trims the. lower thread. In the movement of the lever 29, the roller 31, engages the tail piece of the work clamp, and the latter is raised to place the work in position. The cloth having been inserted under the work clamp, the lever 29 is released and the usual spring 81, acts to lower the clamp and, hold the cloth in place. The operator now pulls a connection (not shown) attached to the lower end ofthe lever 29, which rocks the shaft 27 in the opposite direction, and the finger 56 depresses the lug 57, which thru the connection 13", rocks the frame 11 on the pivots 13, to shift thebelt to the fast pulley 6, which starts the mechanism. This movement disengages the'spring' actuated pin 18 from the flange 19, and the spring 17, pulling on the lever 17, rocks the shaft 16. This movement of the lever 17, also moves the trip 54, from behind the arm 52, and the spring pulls said arm inwardly where it will be ready to slip in the path of movement of the lug 53, if the pin 10 fails to properly seat in the notch 9, to cause the stop motion to assume its normal position.

It may here be stated that where the expression normal position is used in the description and claims, it is intended to mean that the stop motion parts are in their initial position and that the pin 10 is accurately seated in the notch 9. Simultaneously with this movement the shaft 16 .positions the nose 35, of the catch or sto 36, in the upward path of movement 0 the latch lever 34. If the needle thread is properly tensioned over the controller wire 48,, it will hold the trip 44 in position to f permit the beveled end of the lever38 to pass the' abutment 45, and assuming the parts operate In their proper predetermined 38, which sequence, the locating of the latch lever 52 in the ath of the lug 53, and the lever 34, in t e path of the nose 35 of the collar, is an immaterial factor, as the parts are so timed and arranged as to permit them to be returned to normal position.

During the operation of makin a buttonhole, the clamp 7, and the associated parts move to the left in Figure 1, which permits the spring actuated finger 18", on the lever 18 to dro in the path of movement of the rod 19*. hen the clamp moves to the right the finger 18", forms an abutment for the rod 19 which causes the crank connection 13 to turn the upper thread trimming blade 18 in position to subsequently sever the thread. When the clamp movesto the right, and the rod 19 is held by the abutment the spring 18 is placed under tension to return the rod and the trimming blade to initial position. Upon operation of the shaft 16, by

the stop motion, when the stitching opera- 7 6 tion is completed, the arm 18 is of course thrown upwardly which removes the lever 18" from the end of the rod 19, and the spring 18 immediately acts to throw the rod toward the right which actuates the trimming blade to sever the needle thread. As-

sume that the buttonhole has been properly formed and the automatic mechanism has returned the parts to normal position, and the machine stops. The operator now pulls the upper end of the lever .29, and rocks the shaft 27, and the roller 33 operating on cam 21, actuates the lowerthread trimming mechoperation of manually lifting the work clamp, the collar 41, engages the lever 38,

"and forces its free beveled end down past the abutment of the trip 44, which at this time is held against the tension of the spring 49, by the tension of the needle thread.

Now let it' beassumed that the needle thread breaks, or becomes unduly slack, or the bobbin thread runs out or stitches have been skipped. Either of these conditions will remove the pressure of the thread on the controller wire 48, and the spring'49,

promptly tends to move the trip toward the end of the lever 38. It follows then that ifthe operator has not observed the condition of the thread he will be warned that something is wrong, '-for immediately the upper end of the lever 29 is ulled to actuate the clamp it-will be foun "impossible to raise said clamp, owing to the. fact that the abutment 45 'is'positioned under the lend'of lever. forms a lock, as shown in full lines &

in Fig. 2. This locking action prevents the link 40 and its collar 41 moving upwardly. Obviously, this prevents the shaft 27 being rocked, and therefore the work. clamp cannot be elevated. The operator now rethreads the needle, or takes up the slack, as the case may be, and as the work is still clamped, the incomplete or damaged buttonhole is restitched in its original gaged position, thereby savingthe expense of replacement and insuring of a perfect buttonhole.

It frequently happens that the cutting blade 90, which is usually controlled and operated by direct connections between the stop motion device and said cutting blade, for instance as shown in thepatent to Allen No. 743213 November 3,1903, sticks in the cloth, or thru lack of power the cam does not stop exactly in the position to permit of the pin 10 engaging in the notch 9. Then this happens, and the lower trimmer is operated, or the machine is restarted, it invariably results in damaging the cutting blade and the delicate mechanism associated therewith. It is to prevent this occurring that I have provided the latches 36 and 52, one of which 52, prevents starting the mechanism, and the other 36, prevents the clamp being raised.

When the usual automatic mechanism (not shown) operated the stop motion and rocked the frame 11 toward normal position to bring the pin 10 in the path of the notch, the trip 54, being free of the latch 52 and the latter being under the influence of the spring 55, quickly positions itself behind the lug 53, as shown in Fig. 7. Now if the notch 9 for any reason fails to be properly positioned to receive the pin 10, the latter-rides on the periphery of the cam, consequently the member 19 cannot return the lever 17 to its nor mal position, therefore the nose 35 of the catch 36, remains in the path of movement of the latch 34, as shown in dotted lines in Fig. 6, and prevents upward movement of the latch.

lVhen. this condition occurs, and is not noticed by the operator, and if the latter starts to raise the clamp or start the mechanism, it follows that neitheFoperation can be performed until the parts are manually moved to their correct normal position. When the machine is turned by hand to normal position, the lever 17 is rocked, which also rocks the shaft 16, and in turn the trip 54 acts to move the latch 52 out of the path of the lug 53.

It'may be stated that the cutting blade cannot assume its normal position until the pin 10, finally seats in the notch 9 in the cam, and as the trimmer blades 22 and 18 swing in the path of the cutting blade, it is of the utmost importance that the parts be so arranged as to insure of the cutting blade being elevated clear of the path of movement of the trimmers before the latter can be operated to avoid bending or breaking of the parts of the machine, or the needle. The details of this invention successfully meet these conditions, and positively insure against starting of the mechanism, or lifting the clamp if the parts do not come back to normal position.

Of course, after the pin is positioned in its notch, the catch 36 is removed from the latch 34, and the clamp can be raised in the usual It follows from the foregoing description that the latches are actuated by the stop motion when starting the mechanism, and that neither the work clamp can be elevated, nor the stitch formin mechanism started, if perchance the cuttmg blade fails to return to normal position, or if the stop motion fails to restore the parts, after the preceding cycle of operation of the parts in the formation of a buttonhole is completed. The mechanism is so arranged as to prohibit the operator throwing the mechanism into power unless the parts have properly completed their work and have been restored.

The mechanism is so, arranged that it preeludes the moving of the parts locked until the trouble or irregularity in the movement of the elements has been removed.

In the formation of the buttonhole, the usual tension devices are released at or about the time of the formation of the end or barring stitches, and the thread has heretofore been pulled thru' all the tension devices from the usual cone or other supply. In this pulling action, the tension devices are re leased to make the barring stitches, while the thread also for the side or purl stitches ,is pulled off while the tension devices are released from the thread. This eliminates excessive drag on the thread, which is the cause of uneven purl stitches and breaking of thread, thereby incurring considerable delay and inconvenience in rapid operation. I have found that if suflicient thread is pulled from the source of supply when the tension devices are released for the formation of the end barring stitches, for making the side or purl stitches, the strain is reduced, and the needle thread is prevented from breaking, and the purl stitches are unform and in general are greatly improved. To this end, at the time the tension devices are automatically released to form the end barring stitches, the action of the parts pulls suflidevice and the supply is entirely dispensed with. This 0 eration occurs when both end barring stitc es are to be formed, consequently when starting the next succeeding buttohole there is rovided sufiicient slack thread to form the rst row of purl stitches.

In providing this means for removing the tension, it has been found to be of considerable advantage to make the parts of such shape as to preclude the slack thread catching or binding. To this end, the plate is so shaped that if the slack thread should loop around it, the thread will readily slip off when it is taken up. It is to accomplish this result that the thread guide plate is of taperin formation.

y invention also performs another function, in that if the bobbin thread runs out, or breaks, the needle thread which has been pulled cannot be worked into the cloth as there is no bobbin thread to cooperate with it. This condition immediately creates slack in the needle thread adjacent the needle, which results in the spring 49 pulling the trip 44 into the path of the end of the lever 38. Hence the work clamp cannot be raised, as previously described. Therefore, while the automatic means employed to prevent raising of the'clamp is normally under the control of the needle thread, this control is such that it is equally effective to preclude the lifting of the clamp if anything unusual happens to the stitches, or the bobbin theread.

What I claim is 1. A sewingmachine having, in combination, stitch-forming mechanism including a reciprocating needle, a work-clamp, means for relatively moving the stitch-forming mechanism and work-clamp to sew a group of stitches, a stop-motion device for arresting the action of the stitch-forming mechanism with the needle out'of the work after the stitches have been formed work-clamp opening means, a locking element forpreventing the opening of the work-clamp dur: ing the stitching, and means connected with said stop-motion device for shifting said locking element to inefi'ective position after the machine has come to rest.

2. A sewing machine having, in combina tion, stitch-forming mechanism including a reciprocatin needle, a work-clamp, means for relative y moving the stitch-forming mechanism and work-clamp to sewa group ofstitches, a stop-motion device including a notched cam and a plunger adapted to' enter the notch in said cam to stop the machine with the needle out of the work, a looking element for preventing the o eningsof the work-clam during the stitc ing, and means actuate by the motion of said pluner in entering said notch for shifting said inking element to inefl'ective position.

3. A sewing machine having, in combination, stitch-formi means including an element adapted to rock said clamp-arm in a direction to release the work, a lock acting on said work-clamp openmg means independently of said clamparm to prevent actuation of the latter, and means connected to :said stop-motion for'rendering said lock inefiective after the machine comes to rest.

5. A sewing machine having, in combination, a stitch-forming mechanism including a reciprocating needle, a work-clamp, including an upper pivotally mounted clamparm, a stop-motion device, manually operated means for rocking said clamp-arm to release the work, a lock'for preventing manual operation of said means, and connections with said stop-motion for rendering said lock inefiective after the machine has been stopped.

6. A sewing machine having,in combination, a stitch-forming mechanism includinga reciprocating needle, a work-holder in-' cluding an upper pivotally mounted clamparm, a stop-motion device including a notched cam and a plunger adapted to enter the notch in said cam to stop the machine, manually operated means for rocking said clamp-arm to release the work, a lock for preventing manual operation of said means, and connections actuated by said plunger during its motion into the notch in said cam for rendering-said lock ineflective at the end of a stitching period.

7. A sewing machine having, in combination, a-stitch-forming mechanism including a reciprocating needle, a work-holder including an upper pivotally mounted clamparm treadle controlled meansfor rocking said clamp-arm to release the work, a

thread-cutter connected to said treadle-controlled means and movable across the needle path to sever the sewing thread, a lock' for preventing operation of said treadlecontrolled means during the sewing, and means connected to said stop-motion for rendering said lock inefiective after the needle has been lifted clear of the work on its last ascent. a

8. Asewing machine having, in combinamechanisnr including a reciprocating need 6, a main-shaft, a workclamp, a stop-motion device including a notched cam and a plunger adapted to enter the notch in said cam to stop the machine at the completion of the last revolution of the main-shaft, a work-clamp opening device, a lock for preventing operation of the workclamp opening device during the sewing and connections actuated by said plunger in moving into said notch at the completion of the last revolution of the main-shaft for rendering said lock ineffective.

9. A buttonhole machine including stitching mechanism, a work clamp, stop motion mechanism, manual means for raising the work clamp, and a latch automatically controlled by the stop motion mechanism to prevent manually lifting the work clamp should the stop motion fail to assume its normal position when stopping the stitching mechamsm.

10. A buttonhole machine including stitching mechanism, a work clamp, a cutter blade, stop motion mechanism, and a latch automatically controlled by the stop motion mechanism to prevent manually lifting the work. clamp should the stop motion or the cutter blade fail to assume normal position when stopping the stitching mechanism.

11. A buttonhole machine including a work clamp, a stop motion, manual means for raising the Work clamp, and automatic means to prevent manual operation of the work clamp until the stop motion returns to normal position.

12. A buttonhole machine including a work starting mechanism, a stop. motion, and means for preventing raising of the work clamp or operation of the starting mechanism until the stop motion is in normal position and stops the buttonhole machine at a predetermined position.

13. A buttonhole machine including a work clamp, starting mechanism, a stop motion, and latches to prevent raising the work clamp or operating the starting mechanism until the stop motion is in normal position.

14. A buttonhole machine, comprising stitch forming mechanism, a cutting blade and a work clamp, and automatic means for preventing lifting the work clamp or starting the stitch forming mechanism at any time while the cutting blade is below its normal or elevated position.

15. A buttonhole machine comprising a cutting blade, means for operatin the cutting blade, a thread trimming bla e, means actuated independently of and irrespective of the cutting blade operating means for operating the trimmer blade, a work clamp, .and automatic means for preventing operation of the trimmer blade when the cutting blade is below the normal or elevated posi tion.

16. A buttonhole machine comprising a said means being controlled by the stop motion or the tension of the thread.

17. A buttonhole machine comprising a work clamp, stop motion, a tension device, a latch to preclude starting the mechanism if the stop motion stops in an abnormal position, and means to prevent the lifting of the work clamp when the thread is slack or breaks, said means being controlled by the stop motion or the tension of the thread.

18. A buttonhole machine comprising a work clamp, a tension device, means for manually operating the work clamp, 21. connection with the means for manually opera'ting the work clamp, and a trip normally the tension of the thread but adapted to move into the path of the connection when.

the thread slacks or breaks to preclude lifting of the work clamp.

19. A buttonhole machine comprising a work clamp, a trimmer, a manually operable lever for lifting the-work clamp and operating the trimmer, a connection extending from the lever, a trip normally held out of the path of the connection by the tension of the thread but adapted to be-thrown into the path of said connection when the thread breaks or becomes slack to preclude the lifting of the work clamp or the operation of the trimmer.

20. A buttonhole machine comprising stitching mechanism, a work clamp, a cutting blade, a stop motion, means for operating the work clamp, means for preventing the lifting of the work clamp if the thread breaks or becomes slack, and means under the control of the stop motion for preventing the starting of the stitching mechanism if the cutting blade is below its normal elevated position and preventing the lifting of the work clamp.

21. A buttonhole machine comprising a work clamp, a cutting blade, upper and lower thread trimming blades, one of which is operated irrespective of the cutting blade, and automatic means for preventing the operation of the thread trimming blades or lifting the work clamp when the cutting vent lifting the work clamp until the stop motion is in normal position, and automatic means operated by the stop motion to control the position of the latch.

23. A buttonhole machine comprising a work clamp, a rock shaft having an arm to raise the work clamp, a stop motion, a latch between the rock shaft and the stop motion to prevent lifting the work clamp until the stop motion is in normal position, and means connected with the rock shaft to prevent raising the work clamp if the thread breaks or becomes slack.

24. A buttonhole machine comprising a work clamp, a thread trimmer, a stop motion, a connection operated by the stop motion to control the operation of the thread trimmer, a latch, means for actuating the latch to prevent subsequent operation of the stop motion should the latter not return to normal position, and means on the connection for removing the latch to its normal position when the stop motion assumes its normal position.

25. A buttonhole machine comprising a work clamp, a thread trimmer, a stop motion, a connection between the stop motion and the thread trimmer to control the operation of the latter, a trip on said connection, a locking element on said connection, a latch operated by the trip and adapted to be interposed in the path of movement of the stop motion to prevent its subsequent operation if it fails to reach its normal position to preclude subsequent operation of the mechanism, and a latch with which the locking element cooperates to preclude lifting of the work clamp if the stop motion fails to stop in its proper normal position.

26. A buttonhole machine comprising stitching mechanism, a work clamp, and a cutting blade, and automatic means controlled by the tension of the thread to prevent lifting of" the clamp when the bobbin thread breaks or the supply is exhausted.

27. A buttonhole machine including a work clamp, and means actuated by the tension of the thread to prevent lifting) of the clamp when the thread breaks or ecomes slack.

28. A buttonhole machine comprising stitching mechanism including upper and lower thread trimming mechanism and a work clamp, means for automatically operating the upper thread trimming mechanism, manual means for operating the lower thread trimming mechanism first and subsequently raising the work clamp.

29. A two thread buttonhole machine comprising upper and lower thread trimming devices, a stop motion which when operated actuates the upper thread trimming device and severs the upper thread, a cloth clamp, manual means to operate the under thread trimming mechanism and first sever the under thread and then raise the cloth clamp.

30. A buttonhole machine comprising stitching mechanism including upper and under thread mechanism, a needle, a work clamp, and a cutting blade, and automatic means controlled by the tension of the needle thread to prevent lifting of the clamp when the under thread breaks or the supply is exhausted.

31. A buttonhole machine comprising stitch forming mechanism, a work clamp, manual means for raising the work clamp and starting the stitching mechanism, a stop motion device, and means associated with the means for raisin the Work clamp to prevent manual operation of said work clamp if the predetermined stitches are improperly formed.

32. A buttonhole machine comprising stitching mechanism, a work clamp, means for starting the stitching mechanism, said means being so positioned that when the movement is reversedthe work clamp will be raised, and locking mechanism to prevent raising the work clamp if the stop motion fails to assume its normal position.

33. A buttonhole machine including a needle bar, an operating shaft therefor, a work clamp, means for manually operating the work clamp'in one direction, a stop motion, a latch controlled by the stop motion to prevent lifting of the work clamp at all times until the operating shaft is stopped at a predetermined position by the stop motion, and means on the manual means for operating the work clamp to cooperate with the latch to prevent manual operation of said work clamp. In testimony whereof I aifix my signature in the presence of two witnesses.

HENRY o. MILLER.

Witnesses:

ALoNzo KNAPPEN, ELEANOR F. J ELF.

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