JP2010068850A - Sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewing machine with a lubricating device capable of adjusting an amount of oil supply on a minute amount range and automatically and periodically feeding an appropriate amount of lubricating oil to a hook of a sewing machine in the sewing machine with a lubrication-free hook. <P>SOLUTION: This sewing machine includes: a shuttle race 13 rotating operatively connected to an upper shaft of the sewing machine and formed with a groove 26 in its inner circumferential side; a shuttle hook 14 stored in the shuttle race 13 and formed with a synthetic resin rail 16 fitted in the groove 26 of the shuttle race 13; an opening portion 31 formed at a predetermined position of the shuttle race 13 so as to expose the rail 16 of the shuttle hook 14; a nozzle 37 having a discharge outlet 46 disposed to face the opening portion 31 when the sewing machine is stopped; an oil tank 33 for storing lubricating oil; a pump 34 having one end side communicating with the nozzle 37 and discharging the lubricating oil from the oil tank 37, from the discharge outlet 46, and a control means 4 actuating the pump 34 operatively connected to the energization of a power supply of the sewing machine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sewing machine including an oil supply device that periodically and automatically supplies oil to a non-oil filler.

  The sewing machine hook provided in the sewing machine has the inner hook built into the outer hook so that the convex rail fixed to the outer periphery of the inner hook fits into the rail groove of the outer hook. A seam is formed by the outer hook rotating at high speed in conjunction with the upper shaft. In general, the inner hook and outer hook are made of stainless steel, steel, etc., so the inner hook and outer hook are likely to wear due to frictional contact. It was. Conventionally, in order to reduce the friction between the inner hook and the outer hook, the inner hook rail is formed of a synthetic resin, an inorganic material, or the like (see, for example, Patent Document 1) or the entire surface of the inner hook. Known is a material in which a skin made of a material containing a synthetic resin is formed (for example, see Patent Document 2).

  A conventional sewing machine equipped with a sewing machine hook made of stainless steel, steel, etc. is equipped with a fueling device to improve the durability of the sewing machine hook, but a part or the whole of the inner hook as described above is synthesized. A sewing machine provided with a sewing machine hook formed of resin or the like does not require oil supply to the sewing machine hook (so-called oil-free hook), and generally does not include an oil supply device.

JP-A-6-238084 JP 7-000664 A

  However, even a sewing machine equipped with an oil-free kettle as described above is used when a single drop (about 0.05 to 0.1 cc) of oil is used per day, compared to when it is used without refueling. It has been reported that the service life of the sewing machine extends almost 2-3 times. Accordingly, there is a demand for a sewing machine including an oil supply device that automatically supplies oil to the sewing machine hook even if the sewing machine includes an oilless hook. The conventional oil supply device proposed to satisfy such a demand is difficult to adjust the oil supply amount in a very small range, and the sewing product becomes dirty due to the wear powder of the rails when the oil supply is more than necessary, On the other hand, there was a problem that the lubrication amount was insufficient and the durability of the sewing machine was lowered.

  Therefore, in view of such a point, the present invention adjusts the amount of oil supply in a very small range in a sewing machine equipped with an oilless hook, and automatically and periodically supplies lubricating oil with an appropriate amount of oil to the machine hook. An object of the present invention is to provide a sewing machine equipped with a refueling device that can perform the above operation.

  In order to achieve the above-described object, the sewing machine according to claim 1 rotates in conjunction with the upper shaft of the sewing machine and is accommodated in the outer hook having a rail groove formed on the inner peripheral side thereof and the outer hook. And a sewing machine having an inner hook formed with a synthetic resin rail that fits into the rail groove of the outer hook, and formed at a predetermined position of the outer hook so that the rail of the inner hook is exposed. An opening, a nozzle having a discharge port arranged to face the opening when the sewing machine is stopped, an oil tank for storing lubricating oil, and one end side communicated with the nozzle, and lubrication from the oil tank A pump that discharges oil from the discharge port, and a control unit that operates the pump in conjunction with energization of a power source of a sewing machine are provided.

  According to the sewing machine configured as described above, the control means operates the pump every time the power source of the sewing machine is energized to feed the lubricating oil from the oil tank through the nozzle to the inner pot. Since the rail of the outer hook is exposed to the exposed opening of the outer hook, a fixed amount of oil is automatically and periodically applied to the sliding surface of the outer hook rail groove and the inner hook rail. It becomes possible to supply to.

  The sewing machine according to claim 2 rotates in conjunction with the upper shaft of the sewing machine, and is stored in the outer hook having a rail groove formed on the inner peripheral side thereof, A sewing machine having an inner hook in which a rail made of synthetic resin that fits into the rail groove is formed, and an opening formed at a predetermined position of the outer hook so that the rail of the inner hook is exposed, and the sewing machine A nozzle having a discharge port disposed so as to face the opening at the time of stopping, an oil tank for storing lubricating oil, one end side communicating with the nozzle, and lubricating oil from the oil tank from the discharge port A pump to be discharged, a counter for counting the number of times of thread trimming signal generation, an input device for setting and inputting the number of times of occurrence of an arbitrary thread trimming signal, and the count number of the counter is preset and input by the input device Generation of a thread trimming signal Upon reaching the number, characterized in that it comprises a control means for actuating the pump.

  According to the sewing machine configured as described above, the control unit operates the pump each time the count number of the counter reaches the number of times of the yarn trimming signal set and input in advance by the input device, Lubricating oil from the oil tank is supplied to the opening of the outer hook through which the rail of the inner hook is exposed through the nozzle, so that the rail groove of the outer hook and the rail of the inner hook It is possible to automatically and periodically supply a fixed amount of oil to the sliding contact surface. In addition, by changing the number of times the thread trimming signal is generated and set in advance by the input device, the frequency of supplying the lubricating oil to the sewing machine can be adjusted, and the lubricating oil of an appropriate amount can be supplied.

  The sewing machine according to claim 3 rotates in conjunction with the upper shaft of the sewing machine, and is accommodated in the outer hook having a rail groove formed on the inner peripheral side thereof, and the outer hook gauge. In a sewing machine having an inner hook formed with a synthetic resin rail fitted in the groove, an opening formed at a predetermined position of the outer hook so that the rail of the inner hook is exposed, and the sewing machine A nozzle having a discharge port disposed so as to face the opening when stopped, an oil tank for storing lubricating oil, and one end side communicating with the nozzle, and discharging the lubricating oil from the oil tank from the discharge port An upper shaft encoder for detecting the rotational speed of the upper shaft of the sewing machine, a counter for counting the rotational speed of the upper shaft encoder, an input device for setting and inputting the rotational speed of an arbitrary upper shaft encoder, The count of the counter is Reaches a rotational speed which is previously set and input by the input device, characterized in that it comprises a control means for actuating the pump.

  According to the sewing machine configured as described above, the control means operates the pump every time the count number of the counter reaches the rotation number (number of needles) of the upper shaft of the sewing machine preset and input by the input device. The lubricating oil from the oil tank is supplied to the opening of the outer hook, so that a constant amount of oil is supplied to the sliding contact surface between the outer hook rail groove and the inner hook rail. It is possible to refuel automatically and periodically. In addition, by changing the number of rotations (number of stitches) of the upper shaft of the sewing machine set and input in advance by the input device, the frequency of supplying the lubricating oil to the sewing machine hook is adjusted, and lubricating oil of an appropriate amount of oil is supplied. Can do.

  According to the sewing machine of the present invention, it is possible to significantly extend the life of the sewing machine hook used as an oil-free hook. Further, since it is possible to supply the minimum required amount of oil supply, it is possible to reduce the consumption amount of useless lubricating oil.

  Hereinafter, embodiments of the sewing machine of the present invention will be described with reference to the drawings.

  First, the sewing machine according to the first embodiment will be described with reference to FIGS. 1 is a front view of the sewing machine hook 8 and the oil supply device 32 of the sewing machine according to the first embodiment, and FIG. 2 is a perspective view (A) and a cross-sectional view (B) of the sewing machine hook 8. FIG. 3 is a perspective view of the inner hook 14 of the sewing machine hook 8. FIG. 4 is a front view showing the positional relationship between the ejection position of the sewing machine oil supply device and the sewing machine hook, and FIG. 5 is a block diagram showing the relationship between the main part of the sewing machine and the oil supply device 32. The sewing machine of the second embodiment has the same configuration as that of the first embodiment except for the configuration of the control means 4 of the fuel supply device 32.

  As shown in FIG. 1, the sewing machine according to the first embodiment includes a bed portion 1, an arm portion (not shown) extending in parallel with the bed portion 1 above the bed portion 1, and the arm portion and the bed portion 1. And a pedestal portion (not shown) for connecting the two.

  A sewing machine upper shaft (not shown) that is rotationally driven by a sewing machine motor (not shown) is disposed horizontally inside the arm portion. On the free end side of the arm portion, a needle bar (not shown) that can be moved up and down by a needle bar drive mechanism (not shown) interlocked with the rotation of the upper shaft of the sewing machine is disposed. A needle 2 is attached to the.

  An upper shaft encoder 3 (see FIG. 5) for detecting the rotation amount of the sewing machine upper shaft is disposed on the upper shaft of the sewing machine, and an output signal of the upper shaft encoder 3 is a control means 4 which will be described later. To be sent to.

  A sewing machine lower shaft 5 (see FIG. 2) is horizontally disposed inside the bed 1, and a pulley (not shown) attached to an end of the sewing machine lower shaft 5 and an end of the sewing machine upper shaft. By connecting a pulley (not shown) of the section with a timing belt (not shown), the upper shaft of the sewing machine and the lower shaft 5 of the sewing machine are connected so as to rotate synchronously.

  A needle plate 6 is attached to the upper surface of the bed 1, and a needle hole 7 through which the needle 2 passes is formed in the needle plate 6, and a sewing machine hook 8 is below the needle plate 6. 5 is attached.

  Then, the needle 2 and the sewing machine hook 8 are driven in synchronization with the rotation of the upper shaft of the sewing machine driven by the sewing machine motor, and the upper thread passed through the needle 2 and the lower thread wound around the bobbin 9 are used. A stitch is formed on the sewn product on the needle plate 6.

  A power switch 10 (see FIG. 5) for connecting and disconnecting the power source of the sewing machine is disposed on the pedestal, and the electrical signal is input to the control means 4.

  The sewing machine is also provided with a pedal (not shown) for controlling the sewing operation during sewing and a pedal sensor 12 (see FIG. 5) for detecting the depression of the pedal. When the stepping operation is performed, the pedal sensor 12 converts the electric signal into an electric signal and sends it to the control means 4, and the control according to the stepping operation is performed.

  The sewing machine hook 8 includes an outer hook 13 that is rotated by the lower shaft 5 of the sewing machine, and an inner hook 14 that is rotatably accommodated inside the outer hook 13. The inner hook 14 accommodates the bobbin 9. The formed bobbin case 15 is formed.

  As shown in FIG. 3, the inner hook 14 is formed at a cylindrical portion 11 having a bottom portion 19, a flange-shaped rail 16 formed on the outer periphery of the cylindrical portion 11, and an open end portion of the cylindrical portion 11. And a flange portion 18 having an inner hook rotation prevention recess 17. A needle drop hole 45 for introducing the needle 2 into the inner hook 14 is formed in the outer peripheral portion of the cylindrical portion 11 in the vicinity of the inner hook stopper 17. The rail 16 is formed of a synthetic resin, and a thread hook portion 21 is formed on the downstream side in the rotation direction of the outer hook 13 with respect to the inner hook rotation-retaining recess 17, and a thread removal portion (not shown) is formed on the upstream side. ing. A shaft-shaped stud 20 is erected at the center of the bottom 19 of the inner hook 14. The bobbin 9 is attached to the stud 20 by being inserted through the central hole 22. A notch 23 is formed at the tip of the stud 20, and the bobbin 9 can be prevented from coming off by engaging the notch 23 with an engaging piece 24 of the bobbin case 15.

  As shown in FIG. 2, the outer hook 13 is fixed to the tip of the sewing machine lower shaft 5 by screwing the bottom portion, and a substantially cylindrical outer peripheral portion is formed from the bottom portion. A sword tip 25 is formed on the outer peripheral portion of the outer hook 13 for catching a loop of the upper thread formed on the needle tip of the needle 2. A rail groove 26 is formed on the inner surface of the outer peripheral portion of the outer hook 13, and the rail 16 of the inner hook 14 is formed in the rail groove 26. The rail groove 26 of the outer hook 13 and the rail 16 of the inner hook 14 constitute a sliding surface that rotates while being rubbed with the rotation of the outer hook 13.

  Further, as shown in FIGS. 1 and 2, a detent member 27 is fixedly disposed on the bed portion 1 at a front position of the inner hook 14. A detent projection 28 that fits into the inner hook detent recess 17 is formed. Then, the inner hook 14 is prevented from rotating following the outer hook 13 by the fitting of the anti-rotation protrusion 28 and the inner hook anti-rotation recess 17.

  The rail 16 may be formed of an inorganic material instead of the synthetic resin. Further, instead of the inner hook 14 as described above, a coating is formed on the inner hook 14 made of stainless steel, steel, or the like only on the rail 16 portion or on the entire inner hook 14 with a synthetic resin, an inorganic material, or the like. Also good.

  Further, a thread trimming device (not shown) for cutting the upper thread and the lower thread is disposed inside the bed portion 1. This thread trimming device is provided with a fixed blade and a movable blade (both not shown), and a thread trimming mechanism interlocked with the movable blade is driven by a thread trimming solenoid 30 (see FIG. 5) to The upper thread and the lower thread extending below 7 are cut.

  The thread trimming solenoid 30 is connected to the output side of the control means 4. When sewing, the pedal sensor 12 detects a backward stepping operation of the pedal, and when the upper shaft encoder 3 detects a predetermined amount of rotation of the sewing machine upper shaft, a thread trimming signal is generated. Then, the control means 4 makes the thread trimming solenoid 30 energized based on the thread trimming signal, and operates the thread trimming device to cut the upper thread and the lower thread.

  After the thread trimming signal is generated as described above, the needle bar stops at a predetermined stop position, and the sewing machine hook 8 temporarily stops at the stop position as shown in FIG. In the lower portion of the outer hook 13 of the sewing machine hook 8 in the stopped state, as an opening for introducing the lubricating oil ejected from the nozzle 38 of the nozzle 37 of the oil supply device 32 described later into the outer hook 13. The window portion 31 is formed. And the rail 16 of the inner hook 14 is exposed to the window part 31 as an opening part in the stop position shown in FIG.

  An oil supply device 32 is disposed below the sewing machine hook 8 of the bed portion 1. The oil supply device 32 includes an oil tank 33 for storing lubricating oil, an electric pump 34 for pumping the lubricating oil from the oil tank 33, a pumping pipe 35, and a discharge pipe 36. Further, the distal end portion of the discharge pipe 36 has a discharge port 46, and a nozzle 37 is connected to the discharge port 46. The nozzle 37 is supported so that the nozzle outlet 38 at the tip thereof faces the window 31 of the outer hook 13. Note that the amount of lubricating oil ejected by one operation of the electric pump 34 by the oil supply device 32 is extremely small (about 0.05 to 0.1 cc). The electric pump 34 is connected to the control means 4 (see FIG. 5), and operates at a predetermined timing to supply oil.

  The sewing machine hook 8 stops at a stop position as shown in FIG. 4 after the thread trimming signal is generated. The nozzle 37 of the fueling device 32 is arranged so that the jet outlet 38 faces the window 31 of the outer hook 13 of the sewing machine hook 8 at the stop position. 38 is disposed in a range of 60 degrees with respect to the position of the window 31 (a range of 120 to 180 degrees with respect to the sword tip 25).

  As shown in FIG. 5, the sewing machine control means 4 includes a CPU 40, a ROM 41, and a RAM 42.

  An upper shaft encoder 3, a pedal sensor 12, and a sewing machine power switch 10 are connected to the input side of the control means 4. Also connected to the input side of the control means 4 is an input device 39 for presetting and inputting the number of times of thread trimming signal generation (number of times of operation of the thread trimming device) until the electric pump 34 of the oil supply device 32 is generated. Has been.

  The ROM 41 stores the number of rotations of the upper shaft of the sewing machine required until a thread trimming signal is generated. The RAM 42 stores the number of times of thread trimming signal generated and input by the input device 39. The CPU 40 is connected to a thread trimming counter 43 that counts the number of times the thread trimming signal is generated. The thread trimming counter 43 stores a new count number in the RAM 42 every time a thread trimming signal is generated, and resets the count number to 0 when the count number reaches a preset number of times. It is like that.

  Further, the electric pump 34 of the oil supply device 32 and the thread trimming solenoid 30 of the thread trimming device are connected to the output side of the control means 4.

  Below, operation | movement of the sewing machine of 1st Embodiment is demonstrated.

  First, before sewing, an operator considers an appropriate amount of oil to be supplied to the sewing machine 8 in advance, and the number of times a thread trimming signal is generated until the input device 39 supplies oil once (the above-mentioned thread trimming signal). When the number of times of operation of the apparatus is set and inputted, the number of occurrences is stored in the RAM 42.

  At the time of sewing, when the pedal sensor 12 detects a backward stepping operation of the pedal, and the upper shaft encoder 3 detects the rotation of the upper shaft of the sewing machine having a predetermined rotational speed stored in the ROM 41, a thread trimming signal is generated. appear. When this thread trimming signal is sent to the CPU 40, the thread trimming counter 43 counts the number of times that the thread trimming signal is generated, and sequentially stores a new count number in the RAM.

  When the count number of the thread trimming counter 43 reaches the number of occurrences of the thread trimming signal set and input in advance, the thread trimming counter 43 resets the count number to 0 and activates the electric pump 34 of the oil supply device 32. Thus, the lubricating oil is ejected from the ejection port 38 of the nozzle 37 toward the window 31 of the sewing machine hook 8, and the inside of the outer hook 13, that is, on the sliding surface of the rail groove 26 of the outer hook 13 and the rail 16 of the inner hook 14. Lubricating oil is supplied.

  Thereafter, as described above, the thread trimming counter 43 counts the number of occurrences of the thread trimming signal, and operates the electric pump 34 to supply oil to the sewing machine hook 8 every time the set number of occurrences is reached.

  According to the sewing machine of the first embodiment as described above, when the count number of the thread trimming signal of the thread trimming counter 43 reaches the number of occurrences set and input in advance by the input device 38, the electric pump 34 is operated. Since the lubricating oil is configured to be supplied to the sewing machine hook 8, it is possible to supply a fixed amount of oil to the sewing machine hook 8 automatically and periodically. In addition, by appropriately setting the number of times the thread trimming signal is generated by the input device 39, for example, the oil supply amount is adjusted according to the size, material, etc. of the sewing machine hook 8, and lubricating oil with an appropriate oil supply amount is supplied within a very small range. Is possible.

  Next, the sewing machine of the second embodiment will be described. FIG. 6 is a block diagram showing the relationship between the main part of the sewing machine and the oil supply device 32 according to the second embodiment.

  In the sewing machine according to the second embodiment, a needle number counter 44 is connected in place of the thread trimming counter 43 connected to the CPU 40 according to the first embodiment. In addition, the input device 39 can set and input the number of rotations (number of stitches) of the upper shaft of the sewing machine required for one refueling.

  The operation of the sewing machine according to the second embodiment will be described below.

  First, before sewing, the number of rotations of the upper shaft of the sewing machine (number of stitches) required for the operator to supply oil once with the input device 39 in consideration of an appropriate amount of oil to be supplied to the sewing machine hook 8. Is set and input, the number of occurrences is stored in the RAM.

  At the time of sewing, the stitch number counter 44 counts the number of rotations (number of stitches) of the upper shaft of the sewing machine detected by the upper shaft encoder 3 and sequentially stores the new count number in the RAM 42.

  When the count number of the needle number counter 44 reaches the rotation number (number of stitches) of the upper shaft of the sewing machine set and inputted in advance, the needle number counter 44 resets the count number to 0 and the electric pump of the oil supply device 32 34 is operated, the lubricating oil is ejected from the ejection port 38 of the nozzle 37 toward the window 31 of the sewing machine hook 8, and the lubricating oil is supplied into the outer hook 13.

  Thereafter, in the same manner as described above, the needle number counter counts the number of rotations (number of needles) of the upper shaft of the sewing machine, and every time the set number of rotations is reached, the electric pump 34 is operated to supply oil to the sewing machine 8.

  According to the sewing machine of the second embodiment as described above, when the count number of the needle number counter 44 reaches the rotation number (number of needles) of the upper shaft of the sewing machine preset by the input device 39, the electric pump 34 is turned on. Since it is configured to operate and supply the lubricating oil to the sewing machine hook 8, it is possible to automatically and periodically supply a certain amount of oil. In addition, by appropriately changing the number of rotations (number of needles) of the upper shaft of the sewing machine set and input in advance by the input device 39, it is adjusted to an appropriate oil supply amount within a very small range, for example, according to the size or material of the sewing machine hook 8 It is possible to refuel.

  In the first and second embodiments, the input device 39 counts the number of times the thread trimming signal is generated (number of times the thread trimming device is operated) and the number of rotations of the upper shaft of the sewing machine (number of needles). When the number reaches, the electric pump 34 is operated to supply oil, but the electric pump 34 may be operated in conjunction with the energization of the power switch 10 of the sewing machine.

  In addition, this invention is not limited to the said embodiment, It can change variously as needed.

1 is a front view of a sewing machine hook and a fueling device of a sewing machine according to a first embodiment of the present invention. (A) is a perspective view of a sewing machine hook of the sewing machine according to the first embodiment of the present invention, (B) is a cross-sectional view of the same The perspective view of the inner hook of the sewing machine which concerns on 1st Embodiment of this invention. The front view which shows the positional relationship of the ejection position of the oil supply apparatus of the sewing machine which concerns on 1st Embodiment of this invention, and a sewing machine hook. The block diagram which shows the relationship between the principal part of the sewing machine of 1st Embodiment of this invention, and a fuel supply apparatus. The block diagram which shows the relationship between the principal part of the sewing machine of 2nd Embodiment of this invention, and a fuel supply apparatus.

Explanation of symbols

2 Needle 3 Upper shaft encoder 4 Control means 10 Power switch 12 Pedal sensor 13 Outer hook 14 Inner hook 16 Rail 26 Rail groove 30 Thread trimmer solenoid 32 Lubricator 33 Oil tank 34 Electric pump 35 Pumping pipe 36 Release pipe 37 Nozzle 43 Thread trimmer Counter 44 Number of stitches counter

Claims (3)

Synthetic resin rails that rotate in conjunction with the upper shaft of the sewing machine and that have a rail groove formed on the inner peripheral side thereof, and are accommodated in the rail and are fitted in the rail groove of the outer hook. In a sewing machine having an inner pot formed with
An opening formed at a predetermined position of the outer hook so that the rail of the inner hook is exposed; and a nozzle having a discharge port arranged to face the opening when the sewing machine is stopped;
An oil tank for storing lubricating oil;
A pump having one end side communicating with the nozzle and discharging the lubricating oil from the oil tank from the discharge port;
And a control means for operating the pump in conjunction with energization of the power source of the sewing machine. Synthetic resin rails that rotate in conjunction with the upper shaft of the sewing machine and that have a rail groove formed on the inner peripheral side thereof, and are accommodated in the rail and are fitted in the rail groove of the outer hook. In a sewing machine having an inner pot formed with
An opening formed at a predetermined position of the outer hook so that the rail of the inner hook is exposed; and a nozzle having a discharge port arranged to face the opening when the sewing machine is stopped;
An oil tank for storing lubricating oil;
A pump having one end side communicating with the nozzle and discharging the lubricating oil from the oil tank from the discharge port;
A counter that counts the number of times the thread trimming signal is generated,
An input device for setting and inputting the number of occurrences of an arbitrary thread trimming signal;
A sewing machine comprising: control means for operating the pump when the count of the counter reaches the number of occurrences of a thread trimming signal preset and input by the input device. An outer hook that rotates in conjunction with the upper shaft of the sewing machine and has a rail groove formed on the inner periphery thereof, and a rail made of synthetic resin that is housed in the outer hook and fits into the outer hook rail groove. In a sewing machine having an inner pot formed,
An opening formed at a predetermined position of the outer hook so that the rail of the inner hook is exposed; and a nozzle having a discharge port arranged to face the opening when the sewing machine is stopped;
An oil tank for storing lubricating oil;
A pump having one end side communicating with the nozzle and discharging the lubricating oil from the oil tank from the discharge port;
An upper shaft encoder for detecting the rotational speed of the upper shaft of the sewing machine;
A counter that counts the rotation speed of the upper encoder,
An input device for setting and inputting the rotational speed of an arbitrary upper shaft encoder;
And a control means for operating the pump when the count of the counter reaches a rotational speed preset by the input device.

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