JPH0440993A - Needle plate elevating type sewing machine - Google Patents

Abstract

PURPOSE:To miniaturize a needle plate driving mechanism to elevate and drive a needle plate by providing a needle plate driving means for moving and driving the needle plate and providing a presser foot member for pressing working cloth onto the needle plate and an elastic energizing member for elastically energizing the presser foot member to the needle plate. CONSTITUTION:In a bed part 2, a needle plate driving mechanism 14 is provided to elevate and drive a vertically movable needle plate 6. A pressing mechanism 22 is arranged on the upper surface of the needle plate 6 counter to a feed dog 12 and composed of a presser foot member 23, which is almost rectangularly shaped and presses working cloth W onto the needle plate 6 while being composed of a thin spring steel plate, and an elastic energizing member 24 which is arranged in the almost right half of a notched part 4c, composed of the thin spring steel plate, elastically energizes the presser foot member 23 to the needle plate 6 and almost trapezoidally shaped when observing the front face. Then, the elastic energizing member 24 is integrally formed at the right end part of the cloth presser foot 23. Even when the needle plate 6 is moved to the highest position, rising position or falling position, the elastic energizing force of the presser foot member 23 is not affected by the driving force of elevating and driving the needle plate 6 at all. Then, the needle plate driving mechanism 14 can be made compact and simple only to transmit the small driving force required for moving and driving the needle plate 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for moving the throat plate into three positions: the uppermost position, the raised position, and the lowered position.
The present invention relates to a sewing machine with an elevating throat plate configured to be movable over various positions, and particularly to one in which the throat plate is provided with a cloth presser mechanism for pressing work cloth against the upper surface of the throat plate.

[Prior art]

In general, a needle bar vertical drive mechanism that moves the needle bar up and down, a needle bar swing drive mechanism that swings the needle bar, a feed dog drive mechanism that drives the feed dog in the vertical and front-back directions, and an upper thread catcher are used. These mechanisms are driven in synchronization by the rotation of the upper shaft and lower shaft driven by the sewing machine motor, and the needle bar is moved up and down and swung while elastically biased against the needle plate from above. BACKGROUND ART Various electronically controlled zigzag sewing machines have been put into practical use that are capable of performing straight stitches, pattern stitches, etc. on a workpiece cloth by transporting the workpiece cloth in cooperation with a presser foot and a feed dog.

By the way, in this zigzag sewing machine, the needle bar descends and reaches the bottom position after inserting the work cloth, and is slightly (approximately 2 m) from the lowest position.
5) When the upper thread is raised, that is, as shown in FIG. 8 according to the embodiment, the needle thread portion from the work cloth W to the eyelet 10a becomes loose near the eyelet 10a of the sewing needle 10, and the needle thread initial loop 29
a is formed, the tip 26a of the upper thread catcher engages with this upper thread initial loop 29a and rotates, so this upper thread initial loop 29a expands and the upper thread and lower thread become intertwined. It looks like this.

Normally, when the needle bar moves up and down at the swing center position, that is, at the needle bar position during straight sewing, when an appropriate size initial loop of the needle thread is formed, the tip of the needle moves to this initial loop of the needle thread. The meeting timing of the tip of the sword is adjusted so that they engage.

Therefore, in the case of a pattern in which the needle bar swings to the right and to the left with respect to the swing center position, when the needle bar swings to the right, the timing at which the tip of the sword meets is earlier than when sewing a straight line ( (It may be slower depending on the direction of rotation of the tip), and the tips meet before the initial loop of the upper thread has expanded to an appropriate size, so the tip passes through the initial loop of the upper thread without engaging it. There is a problem that skipped stitches occur.

On the other hand, when the needle bar swings to the left, the timing at which the tip of the blade meets is later than when sewing in a straight line, and the initial loop of the upper thread is sufficiently enlarged, but the initial loop of the upper thread becomes too large. Due to twisting of the upper thread, the upper thread that forms the initial loop of the upper thread may wrap around the sewing needle, and in this case, the needle will pass through without engaging the needle.
Similarly, there is a problem that skipped stitches occur.

Therefore, the inventor of the present application has set the throat plate at the uppermost position where the upper surface of the throat plate is above the upper surface of the feed dog, and at the raised position where the upper surface of the throat plate is above the upper surface of the feed dog and a predetermined short distance lower than the uppermost position. The needle bar is configured to be movable in three positions including a lowered position where the upper surface of the needle plate is below the upper surface of the feed dog and the work cloth can be transferred, and the needle bar is stopped at the lowest position for a predetermined period of time. On the other hand, by moving the needle plate downward from the uppermost position to the raised position within this needle bar stop period and before the tip of the needle thread catcher engages with the needle thread on the sewing needle side, the needle bar is moved to the swinging position. We have proposed a sewing machine with an elevating needle plate that is capable of forming a needle thread initial loop of an appropriate size and shape in the upper thread section from the eye of the sewing needle to the fabric to be worked, regardless of the sewing pattern, and can create a beautiful pattern without skipping stitches. .

For reference, in order to simplify the cloth feeding mechanism, the applicant of the present application has provided an elevating drive means that allows the throat plate to move up and down and drives the throat plate up and down, and also drives the feed dog back and forth only in the front and back direction. We proposed a sewing machine with an elevating throat plate configured as follows (
(See Japanese Patent Application No. 2-54215).

[Problem A to be Solved by the Invention] Normally, the cloth presser member that presses the work cloth is elastically biased from above against the throat plate via the presser bar by a spring member provided in the arm of the sewing machine. is configured to do so.

That is, in the above-mentioned needle plate elevating sewing machine, when the throat plate is moved through three positions, especially when rising from the lowered position to the uppermost position, the elastic biasing force of the presser foot member against the throat plate increases, and this There is a problem in that the throat plate must be raised against a large elastic biasing force, and the throat plate drive mechanism for driving the throat plate up and down becomes larger and more complex.

SUMMARY OF THE INVENTION An object of the present invention is to provide a needle plate elevating type sewing machine that can downsize a throat plate drive mechanism that drives the needle plate up and down.

[Means to solve the problem]

The needle plate elevating sewing machine according to the present invention is a sewing machine equipped with a throat plate provided in a bed section, and has a top position where the top surface of the throat plate is above the top surface of the feed dog, and a top position where the top surface of the throat plate is above the top surface of the feed dog. and a movable throat plate that is movable between a raised position that is a predetermined short distance lower than the highest position and a lowered position where the upper surface of the throat plate is below the upper surface of the feed dog, is driven to move across the three positions. A throat plate driving means is provided, and the throat plate is provided with a cloth presser member for pressing the work cloth on the throat plate and an elastic biasing member for elastically biasing the cloth presser member toward the throat plate.

[Effect]

In the needle plate elevating sewing machine according to the present invention, the upper surface of the throat plate is at the uppermost position above the upper surface of the feed dog, and the upper surface of the throat plate is above the upper surface of the feed dog and is lower than the uppermost position by a predetermined short distance. The throat plate, which is movable between the lower position and the lowered position where the upper surface of the throat plate is below the upper surface of the feed dog, is driven to move through these three positions by the throat plate driving means. Since the cloth pressing member that presses the work cloth onto the throat plate and the elastic biasing member that elastically biases it onto the throat plate are provided on the throat plate, the throat plate can be placed in any of the three positions mentioned above. Even if it moves, the elastic biasing force of the presser foot member has no effect on the driving force that drives the throat plate up and down.

〔Effect of the invention〕

According to the needle plate elevating sewing machine according to the present invention, the above-mentioned [effect]
As explained in the above section, since the throat plate is provided with the presser foot member and the elastic biasing member that elastically biases the presser foot member, the throat plate can be placed in any of the uppermost position, the raised position, and the lowered position. The elastic biasing force of the presser foot member has no effect on the driving force that drives the throat plate up and down, even if it is moved to It can be made small and simple.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

This embodiment is a case where the present invention is applied to an electronically controlled zigzag sewing machine capable of sewing patterns.

Inside the arm of the needle plate elevating zigzag sewing machine, there is a needle bar vertical drive mechanism that independently reciprocates the needle bar 8 up and down, a needle bar swing drive mechanism that swings the needle bar 8 left and right, and a needle bar reciprocating mechanism that moves the thread take-up up and down. A balance drive mechanism is built into the bed section 2, and
It incorporates an upper thread catcher 26 that entangles (knots) the upper thread with the lower thread via the tip 26a, and a feed mechanism that reciprocates only back and forth without driving the feed dog 12 in the vertical direction.
Of these mechanisms, the mechanisms other than the needle bar vertical drive mechanism are generally similar to those of a normal sewing machine, and the thread take-up mechanism, upper thread catcher 26, and both forward and backward movement mechanisms are rotationally driven by the sewing machine motor 33. It is driven via the upper and lower shafts.

Regarding the needle bar vertical drive mechanism and needle bar swing drive mechanism, the first
To explain based on the figure, a needle bar stand 5 arranged vertically on the head 3 is swingably supported at its upper end by a pivot pin 7 fixed to the machine frame 4. A needle bar 8 is supported on the stand 5 so as to be movable up and down, and a sewing needle 10 is attached to the lower end of the needle bar 8.

The pin 9 fixed to the needle bar 8 is connected to the needle bar base 5. slit 11
The front end of this pin 9 is inserted into the machine frame 4 and protrudes forward.
The rack 17 of the rack member 13 is engaged with a drive gear 19 fixed to a drive shaft of a stepping motor 30 for driving the needle bar. are doing. Therefore, the needle bar 8 and the sewing needle 10 are caused to reciprocate up and down by the forward and reverse rotation of the stepping motor 30 for driving the needle bar. The lower end of the needle bar base 5 is connected via a connecting rod 21 to a stepping motor 31 for swinging the needle bar (see FIG. 4). 10 is designed to swing from side to side.

Furthermore, a needle plate drive mechanism 14 is provided within the bed portion 2 to drive the needle plate 6, which is movable up and down, up and down.

Next, regarding the needle plate 6 that can be moved up and down, see Figures 2 and 3.
This will be explained based on the diagram.

A rectangular notch 4C is formed in the machine frame 4 of the bed portion 2, and a needle plate 6 having a U-shape when viewed from the front is disposed approximately on the left half of the notch 4c below the needle bar 8. ing. A guide portion 6b extending in the vertical direction is formed at the left end of the throat plate 6, and a work cloth W is formed at the upper end of the guide portion 6b, extending horizontally to the right from the upper end.
An auxiliary guide part 6c is integrally formed on the lower end of the guide part 6b and extends horizontally to the right from the lower end of the guide part 6b.
Guide holes 6d and 6e are provided at the right end of the auxiliary guide portion 6c.
are formed, respectively, and the throat plate 6 can be moved up and down by inserting guide portions 4a and 4b of the machine frame 4 through these guide holes 6d and 6e, respectively. The throat plate 6 is located at the uppermost position where the upper surface of the heavy duty resting section 6a (the upper surface of the throat plate 6) is at the same height as the upper surface of the bed section 2 and approximately 3 mm above the upper surface of the feed dog 12, as shown in FIG. position, a raised position where the top surface of the throat plate 6 is above the top surface of the feed dog 12 and about 2-cm lower than the highest level 1, and a raised position where the top surface of the throat plate 6 is about 1 inch lower than the top surface of the feed dog 12. It can be moved up and down to 3 positions including a lowered position. Incidentally, the heavy duty placement portion 6a is formed with an oval needle hole (not shown) into which the sewing needle 10 can be inserted, and a feed dog through hole 6f through which the feed dog 12 can move up and down and back and forth. still,
The uppermost position corresponds to the raised position described in the claims, and the raised position corresponds to the lowered position described in the claims.

Next, a throat plate drive mechanism 1 for driving the throat plate 6 up and down.
4, a rack member 18 on which a rack 16 is formed is vertically fixed to the left end surface of the guide portion 6b, and a stepping motor 32 for driving the needle plate is attached with a drive gear 20 that meshes with the rack 16. is attached to the machine frame 4. Therefore, by driving the stepping motor 32, the drive gear 20, the rack 16, the rack member 18
The needle plate 6 is moved up and down to the three positions.

Next, the presser mechanism 22, which is attached to the throat plate 6 and presses the work cloth W onto the throat plate 6, will be explained.

As shown in FIGS. 2 and 3, the presser mechanism 22 is disposed on the upper surface of the throat plate 6 facing the feed dog 12, has a substantially rectangular shape made of a thin spring steel plate, and presses the work cloth W onto the throat plate 6. A material presser member 23 and an elastic biasing member 24, which is disposed approximately on the right half of the cutout portion 4c and is made of a thin spring steel plate and has a substantially trapezoidal shape in front view and elastically biases the cloth presser member 23 toward the throat plate 6. Thus, an elastic biasing member 24 is integrally formed on the right end portion of the presser member 23.

The elastic biasing member 24 includes a connecting portion 24a extending diagonally upward to the right continuously from the right end of the presser foot member 23, a horizontal portion 24b extending rightward from the connecting portion 24a, and a vertical portion extending downward from the right end of the horizontal portion 24b. Section 24C and the cloth receiver, which is wide in the front and rear, extend leftward from the lower end of the vertical section 24c and cover approximately the right half of the notch 4c. It consists of a mounting part 24e that attaches the elongated elastic biasing member 24 to the throat plate 6, and a connecting part 24a, a horizontal part 24b, a vertical part 24c, and a cloth receiver part 24d that elastically biases the presser foot member 23 to the throat plate 6. They are constructed so as to generate an elastic force, and can accommodate the ends of the work cloth W to be sewn inside these. Therefore, the widths of the connecting portion 24a, the horizontal portion 24b, and the vertical portion 24c in the front-rear direction are narrow so that they do not interfere with the transfer of the work cloth W during sewing.

The cloth presser member 23 is attached to the throat plate 6 via an elastic biasing member 24, and the cloth presser member 23 is elastically biased onto the throat plate 6 by the elastic biasing force of the elastic biasing member 24 attached to the throat plate 6. Therefore, even if the throat plate 6 moves to the three positions mentioned above, the elastic biasing force of the presser foot member 23 has no effect on the driving force that drives the throat plate 6 up and down, and the throat plate drive mechanism The fourteen stepping motors 32 can be made small enough to transmit the small driving force required to move the throat plate 6. Note that the presser member 23 is formed with an insertion hole 23a through which the sewing needle 10 is inserted.

The needle thread catcher 26 is disposed immediately below the feed dog 12, and the needle bar swing drive mechanism moves the sewing needle 10 to the right maximum swing position 10 (R) shown by the two-dot chain line or to the right maximum swing position 10 (R) shown by the three-dot chain line. The left maximum swing position 10 (L) shown in the figure and the swing center position 10 shown in solid line
Even when moving to (C), the tip 26a (see Figure 8)
The needle thread 29 on the sewing needle lo side can be captured by the needle LO side.

The forward and backward moving member 28 to which the feed dog 12 is fixed is
At the cloth feeding timing, it is driven to move forward or backward at the height position shown in FIG.

Next, the control system of the sewing machine is constructed as shown in the block diagram of FIG.

The motors 30 to 33 are connected via drive circuits 34 to 37, and the speed volume 40 that outputs the set speed signal Vs is connected to the A/
Via the D converter 41, a start/stop switch 38 instructs to start and stop the sewing operation, a pattern selection switch 39 consisting of a numeric keypad to select a desired sewing pattern, and a timing signal generator 42 are input/output of the control device C. Interface 4
3, respectively.

A brief explanation of the timing signal generator 42 is as follows.
N slits (for example, 72) are provided at predetermined intervals on the peripheral edge of a disc-shaped disk attached to the upper shaft, and a sensor detects these slits using the uppermost position of the sewing needle 10 as a reference position. It outputs signals (phase signals), and by counting these detection signals, each of the stepping motors 30 to 32 is timed and controlled.

The control bag fc is composed of a CPU 45, an input/output interface 43 connected to the CPU 45 via a bus 44 such as a data bus, a ROM 50, and a RAM 60.

The stitch pattern data memory 51 of the ROM 50 stores needle position data for each sewing operation for each of a large number of stitch patterns such as letters, symbols, and marks in correspondence with pattern numbers.

The program memory 52 includes the set speed signal Vs output from the speed volume 40 and the start/stop switch 3.
A control program that controls the motors 31 and 33, respectively, based on the start signal and stop signal output from the timing signal generator 8, the detection signal from the timing signal generator 42, and the stitch pattern data, and the stepping motor 30 for driving the needle bar. A needle bar control program, a control program for needle thread loop formation control, etc. are stored.

The first counter 61 of the RAM 60 stores a count value obtained by counting the detection signal output from the timing signal generator 42 from a phase angle of 0 degrees, which is the top position of the needle bar 8 (the count value is designated as I). Ru.

The second counter 62 stores a count value obtained by counting the number of drive pulses supplied to the stepping motor 30 (the count value is defined as M).

The flag memory 63 includes a needle bar drive stop flag F that is set (data "1") when stopping the driving of the needle bar 8 and reset (data "0") when driving the needle bar 8. Data is stored.

Further, the RAM 60 is provided with various types of memories, counters, etc. that temporarily store the results of calculations performed by the CPU 45.

Next, the routine for controlling needle thread loop formation performed by control bag fC of the sewing machine will be described based on the flowchart of FIG. 6 while referring to the time chart of FIG. 7.

For convenience of explanation, the needle bar control routine, which is processed by interrupting the CPU 45 every 1 m5ec, will be explained in the fifth section.
The process will first be explained based on the flowchart shown in the figure. 5t in the figure (
i=1.2.3,...) is each step.

When the start/stop switch 38 is turned on, a soft timer in the control device C (its measurement time is t) starts measuring, and when an interrupt is generated to the CPU 45 every lm5ec, this control is started. , count value ■
When is "0", that is, when the needle bar 8 is at the highest position, and the count value ■ is cleared (340: Yes), the count value M is also cleared (S41), and the set speed signal Vs from the speed volume 40 is Read (S42)
.

When flag F is reset (S43: Ye
s), based on the count value M and the set speed signal Vs, determine the period for the next Mth drive pulse to be output in the motion equation of the sine curve, which is the motion curve of the needle bar 8, as shown in FIG. NT is calculated by calculation (S44), and when the measured time t of the soft timer and the period NT match and it is the timing to output the drive pulse (S45: Yes), the drive pulse is output to the stepping motor 30 (346). The count value M is incremented by one (347), the soft timer is reset (348), the interrupt processing is ended, and the process returns to the main routine. Note that if the determination is No in S40, the process moves to S43, and if the determination is Yes in S43 and the driving of the needle bar 8 is stopped, and if the determination is NO in 345.
When it is determined that this is the case, the interrupt processing is terminated and the process returns to the main routine.

Next, a routine for controlling needle thread loop formation will be explained.

This control starts when the sewing machine is powered on, resets each counter 61 and 62, and initializes the stepping motor 32 to move the needle bar 8 to the initial setting position (for example, the uppermost position). The initial setting process is executed (S 1 ), and the start/stop switch 38 is turned on (
S2: Yes), when the detection signal from the timing signal generator 42 is input (S3: Yes), the count value ■ is incremented by one (S4), and the count value I
When is Nl, that is, when the phase angle θ1 (phase angle approximately 100 degrees) moves the throat plate 6 to the uppermost position with the end of cloth feeding (S5: Yes), the phase angle θ1 of the drive start timing of the stepping motor 32 The time t1 for driving the stepping motor 32 is determined based on the difference between the phase angle θ2 (phase angle approximately 120 degrees) at the driving end timing and the set speed signal Vs, and then the driving time t1 and the driving pulse are determined. The period T1 of the driving pulse is determined based on the number (nl) (S6), and n1 driving pulses are outputted to the stepping motor 32 for each period T1, and the throat plate 6 has a phase angle θ1.
is moved from the lowered position to the uppermost position 4 m upward over a phase angle θ2 (S7), and the start/stop switch 38 is turned to O.
If it has not been FF (S19: No), the process returns to S3.

When the count value I is N2, that is, when the phase angle θ3 (phase angle approximately 150 degrees) causes the driving of the needle bar 8 to be stopped and the needle plate 6 to be moved to the raised position (S8: Yes), the flag F is set.
is set (S9).

Therefore, the above-mentioned needle bar control 343 is determined to be No,
Driving of the needle bar 8 is stopped at the lowest position. Then, similarly to S6, the period T2 of the drive pulse is calculated (SIO
), n2 driving pulses are output to the stepping motor 32 every cycle T2, and the needle plate 6 is moved 2ml+ from the highest position from the phase angle θ3 to the phase angle θ4 (phase angle 180 degrees).
The workpiece cloth W is moved to the lower raised position (311), that is, as shown in FIG. The needle thread 29 inserted therein forms a needle thread initial loop 29a of a certain size in the needle thread portion from the eye hole 10a to the work cloth W. Then, from phase angle θ4 to phase angle θ5 (phase angle approximately 21
0 degrees), this state in which the upper thread initial loop 29a is formed is maintained. In other words, from the phase angle θ4 to the phase angle θ5
During this period, the sewing needle 10 reaches the right maximum swing position 10 (
The needle thread initial loop 29a is formed at R), the sewing needle 10 is formed at the left maximum swing position 10 (L), and the needle thread initial loop 29a is formed at the swing center position 10 (C) of the sewing needle 10. The thickness of each of the upper thread initial loops 29a is constant, and the tip 2 of the upper thread catcher 26 is attached to this upper thread initial loop 29a.
Since the stitches 6a are securely engaged, it is possible to sew a beautiful zigzag pattern without skipping stitches.

When the count value I is N3, that is, when the phase angle θ5 is such that driving of the needle bar 8 is restarted (312: Yes), the flag F is reset (S13).

Therefore, the determination in step 343 of the needle bar control described above is YES, and the needle bar 8 is driven upward from the lowest position.

When the count value I is N4, that is, the throat plate 6 is
When the phase angle is θ6 (phase angle approximately 280 degrees) to move the motor to the lowered position (314: Yes), the period T4 of the drive pulse is calculated by calculation in the same manner as S6 (S15), and the period T4
n4 driving pulses are outputted to the stepping motor 32 every time, and the needle plate 6 is moved from the raised position to the lowered position 211-downward over the phase angle θ6 to the phase angle θ7 (320 degrees). (S16) Then, within the period from the phase angle θ7 to the phase angle θ1, the feed dog 12 is moved forward or backward, and the work cloth W is transferred.

Further, when the count value I becomes N, that is, when the needle bar 8 moves to the uppermost position (317: Yes), the count value ■ is cleared (S18).

As shown in FIG. 9, the mold holding part 70a of the throat plate 70 is configured to have the same size as the cutout part 71c of the machine frame 71, and is composed of a presser member 72 and an elastic biasing member 24A. The presser mechanism 22A may be configured as follows.

That is, a cloth presser member 72 made of metal or synthetic resin is located on the upper surface of the throat plate 70 facing the feed dog 12A, and presses the workpiece cloth with a cloth presser portion 72a, and an inclined portion 72b that is connected to the cloth presser portion 72a.
A horizontal part 72c extending rightward from the inclined part 72b, a vertical part 72d extending downward from the horizontal part 72c, and an urging part 72e extending leftward from the lower end of the vertical part 72d, and the lower end of the vertical part 72d. is pivotally attached to the right end of the throat plate 70 with a pin 73. Then, the upper end portion of the elastic biasing member (tension spring) 24A is engaged with the biasing portion 72e, while the lower end thereof is engaged with the hook portion 70d extending downward from the throat plate 70,
The elastic biasing force of the elastic biasing member 24A causes the presser member 72 to
may be elastically biased to the throat plate 70. In other words, various cloth presser members provided on the throat plate may be elastically biased to the throat plate by an elastic biasing member provided on the throat plate.

The throat plate drive mechanism 14 is merely an example, and the needle plate drive mechanism 14 may be constructed using various mechanisms, such as an eccentric cam, a crank mechanism, or the like to move the throat plate 6 up and down.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and Fig. 1 is a perspective view showing the internal mechanism of the sewing machine, Fig. 2 is a partial plan view of the bed section showing the main parts, and Fig. 3 is Fig. 2. 4 is a block diagram of the control system of the sewing machine, FIG. 5 is a schematic flowchart of the needle bar control routine executed by interrupt processing, and FIG. 6 is a schematic flowchart of the needle thread initial loop formation control routine. , FIG. 7 is a time chart showing the vertical movement of the needle bar, FIG. 8 is an action diagram illustrating the action of forming an initial needle thread loop by the downward movement of the needle plate, and FIG. 9 is a time chart showing the movement of the needle bar up and down. This is a diagram equivalent to Figure 3. 6, 70... Throat plate, 12... Feed dog, 14... Throat plate drive mechanism, 18... Rack member, 23, 72... Cloth presser member, 24, 24A... Elastic biasing member, 32...
Stepping motor for driving the throat plate. Patent applicant Brother Industries, Ltd. Figure 2 Figure 5 Figure 8 Figure 9

Claims (1)

[Claims] (1) In a sewing machine equipped with a throat plate installed in the bed, the uppermost position where the upper surface of the throat plate is above the upper surface of the feed dog, and the uppermost position where the upper surface of the throat plate is above the upper surface of the feed dog and a predetermined short distance from the uppermost position. The throat plate is movable between a raised position where the upper surface of the throat plate is lower than the upper surface of the feed dog and a lowered position where the upper surface of the throat plate is lower than the upper surface of the feed dog.
A throat plate driving means is provided for moving and driving the needle plate over various positions, and a cloth presser member that presses the work cloth on the throat plate and an elastic biasing member that elastically biases the cloth presser member toward the throat plate are provided on the throat plate. A sewing machine with an elevating needle plate.