摘要:
A lock stitch sewing machine with an automatic thread tension adjusting device is disclosed, wherein the sewing machine has a plurality of thread tension adjusting mechanisms 7, each of which including a pair of thread tension disks 12, 13, one of which is normally pressed by a spring toward the other. A sensor 4 is responsive to the operation of a thread tension releasing lever 20 made by a user with a slight touch applied thereto to give a signal. A CPU1 is responsive to the signal to compare the value of the existing thread tension of the thread tension adjusting mechanisms 7 with a predetermined one. If the value of the existing thread tension is higher than the predetermined one, the CPU1 is operated reduce the value of the existing thread tension to a predetermined one. Thus the tension releasing operation ability is increased.
摘要:
An electromagnetic driving device is provided at a non-rotating part of a sewing machine, thereby to rotate a first magnet via transmission mechanism. A second magnet which is opposite to the first magnet with an appropriate space thereby, is rotatably provided with respect to a bobbin carrier. These magnets keep a certain one rotating relative position by means of the opposing magnetic poles, thereby to transmit rotation of the first magnet to the second magnet. Rotation of the second magnet actuates a tension adjusting mechanism comprising a thread tension adjusting spring provided on the bobbin carrier, via the transmission mechanism so as to adjust the thread tension, and controls the electromagnetic driving device in response to designation of the thread tension. Thus, the tension of the lower thread may be adjusted when attaching the bobbin carrier in the sewing machine.
摘要:
When a pulse motor in an electronic sewing machine is to be subjected to a heavy load, the pulse motor is operated at a slower speed in order to cause the pulse motor to operate at a rate in which it has a maximum torque output. For lesser load conditions, pulse motor speed is allowed to increase. Speed control of the pulse motor follows a generally trapezoidal curve, which curve includes a speed-up section and a slow-down section, and may include a flat section. That portion of the generally trapezoidal curve along which motor speed follows is determined by the distance which the pulse motor is required to move.
摘要:
A sewing machine has a loop taker rotated in horizontal plane and a bobbin carrier contained in the loop taker. The bobbin carrier has an abutment secured thereto and a leaf spring mounted on the abutment and movable to and away from the abutment to adjust a tension applied to a lower thread extending between the abutment and the leaf spring. A plurality of windings are provided on a stationary horizontal plane adjacent the underside of the loop taker. The windings are progressively energized by selective operation of an electric control part to create a revolving magnetic field. A magnet is rotated in accordance with the revolving magnetic field, and the rotation of the magnet is transmitted through a series of gears to a cam which actuates a member influencing the movement of the leaf spring, thereby adjusting the tension applied to the lower thread.
摘要:
An electronic sewing machine includes at least two pulse motors, in which a control detecting device detects all individual operations of the movable members in response to a plurality of functions performed by independent driving sources, such that in each of these functions the machine operates normally. The control detecting device includes two screen interrupting elements each associated with the respective pulse motor and a single photoelectric sensor cooperating with each interrupting element for producing electric signals for operating a microcomputer of the sewing machine to set each of the pulse motors to an initial position.
摘要:
A process for stitching a buttonhole in the forward and reverse fabric feeding directions by means of a zigzag sewing machine including the step of producing one or more of stitches at a critical pattern changing point which will serve as a reference mark for enabling the sewing machine operator to operate the sewing machine as required with ease for the pattern changing operation.
摘要:
This invention relates to a computer controlled sewing machine, and more particularly to such a sewing machine which is incorporated therein with a plurality of feed adjusting switches for giving information to a micro-computer housed in the sewing machine, in order to correct irregularities of forward and backward feed amounts.
摘要:
During stitching a pattern, there is often issued a designation to change the pattern under forming to the other. In such a case total load on a fabric feed control motor and a needle amplitude control motor is temporarily increased. A microcomputer which controls driving of these motors, discriminates the new designation and rotating phase of the sewing machine and drives the fabric feed control motor by means of specific data by mean value of the maximum and the minimum fabric feed control data, instead of the fabric feed control data which is first read out next to said designation. The control amount brought about by difference between said specific data and the fabric feed control data read out prior to said designation which controls as the final fabric feed before said designation, is caused to prevent the maximum available to the sewing machine so that the total load applied to the two motors are reduced when the maximum possible control is given to the needle amplitude control motor in succession to the load on the fabric feed control motor.
摘要:
A stitch-length correcting sewing machine and a stitch-length measuring presser foot assembly used therein are disclosed. The sewing machine and presser foot assembly enables stitches of a predetermined length to be sewn, without the necessity of stitching a trial stitch on a piece of fabric and adjusting the sewing machine to compensate for variations in fabric type and thickness. The presser foot assembly utilizes a presser foot which is detachably securable to a presser bar. A movable presser frame slides on the presser foot as fabric is fed. A potentiometer is fixed to the presser foot and responds to sliding of the presser frame so as to enable distance moved by the presser frame to be ascertained by detecting the resistance of the potentiometer. The presser foot assembly can be used as a fabric sensor responsive to fabric motion in an electronic sewing machine. This enables fabric feed (and, optionally, needle swing) to be varied in accordance with actual motion of the fabric to sew stitches of a predetermined length and to further sew patterns which are properly balanced, independently of fabric type and fabric thickness.
摘要:
An embroidering device for a sewing machine includes an embroidering frame and a first driving member to be connected with the feed dog of the sewing machine for driving the embroidering frame in a direction transverse to lateral swinging and vertical reciprocating directions of a needle bar of the sewing machine. A second driving member is connected with the needle bar support for driving the embroidering frame in the lateral swinging direction of the needle bar.