MXPA97002161A - Sewing machine for oja - Google Patents

Abstract

The present invention relates to a sewing machine for buttonholes comprising: a housing, a bed mounted slidably on said housing between a rest position and a position for sewing, a needle mechanism mounted on said housing and being movable in a reciprocal with respect to said housing, a first motor mounted on the housing, said first motor directly driven said bed between the rest position and the position for sewing, and a second motor mounted on the housing, said second motor driving directly said needle mechanism , the second motor having means to directly drive the bed to allow stitching around the eye

Description

SEWING MACHINE FOR OJALES FIELD OF THE INVENTION The present invention relates to a sewing machine for eyelets. More specifically, the present invention relates to an eyelet sewing machine having a first motor for directly driving the bed and a second motor for directly driving the needle mechanism.

BACKGROUND OF THE INVENTION Buttonhole sewing machines are known per se. For example, a buttonhole sewing machine is currently available from Reece Corporation of Gorham, Maine and is sold under the tradename "Buttonhole Sewing Machine" Series 104-100. The manual service and parts list for this series 104-100 buttonhole sewing machine are incorporated herein by reference. This buttonhole sewing machine is driven by an individual motor. Since only one motor is used, a complex machine is required to drive both the bed frame and the needle bar mechanism. For example, the Reece 104-100 buttonhole sewing machine uses two clutches to make the motor engage either the bedframe or the feed bar mechanism. In addition, a brake is required, so that the head for sewing can be held in a predetermined fixed position. Since the Reece 104-100 buttonhole sewing machine uses complex machinery, it operates at a relatively high noise level and undergoes a significant standstill period whenever maintenance is required. Parts such as clutches and brakes will inherently wear out over time and must be replaced on a regular basis. However, due to the complex machinery, a mechanically qualified machinery does not have the necessary experiences required to replace the clutches and the brake in this buttonhole sewing machine in a satisfactory period. Therefore, a specially experienced mechanics, as with the Reece 104-100 machine, requires replacing both the clutches, the brake, and other components in the Reece 104-100 machine. Clearly, there is a need in the art to provide a sewing machine for buttonholes, which undergoes a shorter period of standstill and operates at a relatively low noise level. To meet this need, Reece tried to modify his buttonhole sewing machine to overcome some of these problems. One attempt included using a reversible motor that included a pair of single-path clutches attached to it. A single-path clutch was used to drive the bed and the other single-path clutch was used to drive the feed bar mechanism. However, in order for this machine to operate properly, a brake was required to stop the engine within 3o accuracy. Unfortunately, after a relatively short period of use, the brake was no longer able to stop the engine within the 3rd required accuracy. In this way, this modified Reece 104-100 machine resulted in a sewing machine for buttonholes that required more maintenance and still had larger amounts of stoppage periods.

COMPENDIUM OF THE INVENTION It is an object of the present invention to create a sewing machine for buttonholes, which eliminates the need to use clutches or brakes to drive the bedplate or the needle bar mechanism. In addition, it is a further object of the present invention to provide an eyelet sewing machine that requires less maintenance and undergoes periods of stoppage and operates at a lower noise level. According to a preferred embodiment that demonstrates other objects, to aspects and advantages of the invention, a sewing machine for buttonholes includes a housing with a bed that slidably mounts on the housing, so that the bed moves in the direction of the sewing. na resting position and a position to sew. A needle mechanism is mounted on the housing and moves reciprocally with respect to the housing. A first motor is mounted on the housing. The first motor directly drives the bed between the rest position and the position for sewing. Also, a second motor is mounted on the housing. The second motor directly drives the needle mechanism.BRIEF DESCRIPTION OF THE DRAWINGS The above objects, aspects, and advantages, and others, of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, in which like reference numerals in the several figures are used to designate similar components, and wherein: Figure 1 is a perspective view of a buttonhole sewing machine according to the present invention; Figure 2 is a front view of the buttonhole sewing machine illustrated in Figure 1; Figure 3 is a partially sectioned top view of the buttonhole sewing machine, according to the present invention; Figure 4 is a side view of the buttonhole sewing machine, according to the present invention; Figure 5 is a partially sectioned side view of the present invention; Figure 6 is an exploded view of a fastening mechanism according to the present invention; and Figure 7 is a side view of the clamping mechanism according to the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE MODALITIES Referring now to Figure 1, there is illustrated an eyelet sewing machine 10 having a housing 12. This buttonhole sewing machine is a modification and improvement of the Sewing Machine for Reece Series 104-100 eyelets. Accordingly, many of the parts of the present invention operate very similarly to the Reece machine and for brevity, the description of those parts has been omitted. A bench 14 is slidably mounted on the housing 12. The housing 12 comprises the fixed frame of the sewing machine. A cutting lever 16 is mounted pivotally on the housing 12. Since the cutting lever 16 is mounted in a conventional manner, and for clarity, the cutting lever 16 will not be illustrated in the remaining Figures. A needle bar mechanism 18 (see Figure 4) is mounted on the housing 12 in such a way that it moves up and down in a reciprocal manner with respect to the housing 12. A second brushless DC 24 motor is mounted on the housing 12. The second motor 24 directly drives the needle bar mechanism 18, via a band transmission 26. As illustrated in Figure 3, the second motor 24 rotates an arrow 28, which is fixedly connected to the pulley 30. The band 26 transmits the rotating force of the motor arrow 28 to the arrow 32 which drives the needle bar mechanism. The arrow 32 is fixedly connected to the pulley 34, which is rotatably driven by the band 26. A cam 36 is fixedly connected to the arrow 32. The cam 36 slidably engages with the bed 14 to cause the bed to move around from the periphery of the buttonhole that is going to be sewn. In this way, the rotation of the arrow 32 causes the actuation of the needle bar mechanism 18 and simultaneously causes the bed 14 to move a distance substantially equal to the length of the stitch, to allow the needle bar mechanism around the periphery of the buttonhole. A pulley 34 with an outer periphery 44 grooved on its opposite axial end is also provided. The outer periphery 44 fluted allows the user to manually rotate the arrow 32 for the purpose of maintenance. Referring now to Figure 4, to adjust the tension on the band 26, the motor 24 is pivotally mounted to the housing 12 about a pivot point 38. A threaded strip 40 receives an internally threaded mounting bracket 42, which is mounted on the motor 24. Accordingly, by rotating a notch within the running bracket 42, the motor 24 can be pivoted towards and away from the housing 12 to vary the tension on the band 26 to a preferred level. A first motor C.D. twenty, brushless, is mounted to the housing 12, being mounted below the table 46. The motor 20 rotates the arrow 48, which is fixedly connected to the pulley 50. The band 22 directly transmits the rotating force from the arrow motor 48 towards pulley 52, which is fixedly mounted on arrow 54. The rotation of arrow 54 drives the mechanism (not shown) to move the frame 14 between the rest position and the position for sewing. In addition, a manual wheel 56 is fixedly attached to the arrow 54 to allow the user to manually rotate this arrow for maintenance purposes. Referring now to Figure 4, the motor 20 includes a band tension adjustment mechanism similar to the mechanism used to adjust the band 26 of the first motor 24. The motor 20 is pivotally mounted to the housing 12 about the pivot point 58. The threaded rod 60 receives an internally threaded mounting bracket 62, which is mounted on the motor 20. Therefore, by rotating a notch inside the mounting bracket 62, the motor 20 can be pivoted towards and away from the table 46. to vary the tension on the band 22.

A control unit 64 is mounted below the motor 20 by a pair of brackets 66. A further portion of the control unit 64, as illustrated in Figure 1, can be mounted directly below the table 46. The unit 64 has an indicator 68 mounted on top of the first motor 24. The control unit 64 is programmed to control the drive of the first motor 20 and the second motor 24. Due to the movement of the bed 14 between the rest position , the position for sewing and the cutting position take place independently of the actuation of the needle bar mechanism, it is preferred that the control unit controls the drive of only one motor at any given time. In other words, in a sequence of operation, assuming that the bed is in the rest position, the control unit 64 will drive the motor 20 to cause the bed to move to the position for sewing. Then, the control unit will no longer drive the motor 20 and will begin to control the drive of the second motor 24 to begin stitch operation. Once the stitch operation is completed, that is, once the entire periphery of the buttonhole has been sewn, the control unit 64 will stop the motor drive 24. Then, the control unit 64 will again operate the motor 20. to move the bench 14 to the cutting position. Once the bench 14 is in the cutting position, the cutting lever 16 is actuated to cut the buttonhole in the fabric. Then, the control unit 64 drives the motor 20 one more time to move the bank back to the rest position. It should be noted that, as is conventional with sewing machines for buttonholes, the cutting step takes place either before or after the stitching procedure. The operator can control the operation of the buttonhole sewing machine by input, via the indicator unit 68, that the motors are to be controlled to operate through a cycle a repair cycle. The complete cycle for the sewing machine for buttonholes is the normal operation sequence and has been described above. The individual step can be used to assist a mechanic when he is servicing the machine, allowing the machine to advance only one step of operating sequence at a time. The repair cycle allows the operator to move the second motor 24 at various speeds. For example, the speed of the motor 24 can be controlled to be between a scale of 80 to 2,000 rpm, with a normal operating speed of between 1250-1500 rpm. However, by operating the second motor at the very low speed of 80 rpm, the operator can place the needle in the precise position around the eyelet. In this way, if for some reason the cycle of stitches had to be interrupted, the operator can turn off the machine, correct the malfunction of the sewing machine, and then use the repair cycle to return the needle to the position necessary to ensure that the buttonhole has been properly sewn around the entire periphery. Consequently, once the precise position of the buttonhole has been obtained, the operator can then set the control unit indicator to the fixing of the complete cycle to allow the buttonhole to be sewn and cut in a normal way. Referring now to FIGS. 2 and 4-7, a pair of gripper arms 70, 72, each has a gripper end 74, 76 attached to its distal ends. The clamping mechanism is pivotally mounted to the housing 12 around the pivot point 78, as illustrated in Figure 7. A coil spring 80 is mounted between the housing 12 and a distal end of the clamping fork 82. The spring 80 is tensioned to impart a left-handed force (as seen in Figure 7) around the pivot point "^ 8 towards the clamping mechanism., the spring 80 maintains the clamping limbs 74, 76 in the vertical position. A pneumatic air cylinder 86 is connected to the clamping forks 82, as illustrated in Figures 5 and 6. By operating the pneumatic switch 84, the operator will cause an air pressure to enter the pneumatic cylinder 86 via the pressure line of the air cylinder 86. air 88 from an external air pressure source (not shown). The actuation of the air cylinder 86 causes the clamping fork 82 to move in a downward manner against the applied force of the spring 80. Consequently, the clamping arm mechanism will rotate in a clockwise direction about the pivot point 78 to make the limbs 74, 76 go down against the upper surface of the bed 14. Accordingly, the clamping fingers 74, 76 will now securely hold a fabric on the upper surface of the bed between the clamping legs 74, 76 and the surface upper of the bed 14. If at any time during the operation sequence, the operator wishes to adjust the position of the cloth, he can simply change the actuation of the switch 84 to cause the ends 74, 76 to intermittently release and reapply the pressure which is being applied on the cloth.

In this way, the user can reposition the fabric in a desired position without fully releasing the clamping force on the fabric. Once the fabric is in the correct position, the user will then stop changing the switch 84 and allow the limbs 74, 76 to retain the position of the fabric securely between the ends 74, 76 and the top of the fabric. bench 14. Having described the currently preferred illustrative embodiment of a new and improved sewing machine for grommets, according to the present invention, it is believed that other modifications, variations, and changes will be suggested by those skilled in the art in view of the teachings established here. Therefore, it should be understood that all these variations, modifications and changes are believed to fall within the scope of the present invention as defined by the appended claims.

Claims (1)

1. - A sewing machine for buttonholes comprising: a housing; a bed mounted slidably on said housing between a rest position and a position for sewing; a needle mechanism mounted on said housing and movable in a reciprocal manner with respect to said housing; a first motor mounted on the housing, said first motor driving said bed directly between the rest position and the position for sewing; and a second motor mounted on the housing, said second motor driving directly said needle mechanism, the second motor having means to directly drive the bed to allow stitches around the eyelet. 2 - A sewing machine for buttonholes according to claim 1, further including a control unit having means for controlling the actuation of said first motor and said second motor. 3. A sewing machine for buttonholes according to claim 2, wherein said control means control the actuation of only one of the first motor and the second motor at any given moment. A. A sewing machine for buttonholes according to claim 2, wherein said control means control the drive of the second motor between a rotational speed ranging from 80 rpm to 2000 rpm. 5. A sewing machine for eyelets according to claim 1, further including a fastening arm having means for selectively holding a fabric, safely, on a top surface of said bed. 6. A sewing machine for buttonholes according to claim 5, wherein said selective support means are pneumatically operated. 7. A sewing machine for eyelets according to claim 6, wherein said support means includes a switch mounted on the upper surface of said bed. 8. A sewing machine for buttonholes according to claim 1, wherein said direct drive means include a cam mounted on a rotary arrow to effect the movement of said bed around a periphery of said eyelet. 9. A sewing machine for buttonholes according to claim 2, wherein said first motor and said second motor are electric motors. 10. A sewing machine for eyelets according to claim 9, wherein said electric motors are C.D. motors, brushless, encoded, rotating. SUMMARY A sewing machine for buttonholes includes a housing (12). A bed (14) is slidably mounted on the housing and moves between a rest position and a position for sewing. A needle mechanism (18) is mounted on the housing and moves reciprocally with respect to the housing. A first motor (24) is mounted on the housing. The first motor directly drives the bed between the rest position and the position to sew. A second motor (20) is mounted on the housing. The second motor directly drives the needle mechanism.