A sewing machine includes a needle plate, a bed portion, a first urging member, a first engagement member, a second engagement member, and a lock release mechanism. The bed portion is configured to support the needle plate. The first urging member is provided inside the bed portion and configured to urge the needle plate upward. The first engagement member is provided on the needle plate. The second engagement member is provided inside the bed portion, and is configured to fix the needle plate in a fixed position by being engaged with the first engagement member of the needle plate pressed downward against an urging force of the first urging member. The lock release mechanism is configured to release the engagement of the first engagement member and the second engagement member.

Provided is a sewing machine that can be reduced in size by employing a simple configuration for a feed dog drive device. A lateral feed drive unit (8) and a vertical drive unit (9) transmit rotation of a drive shaft (7) to a feed dog (3). The feed dog (3) is supported by a swingable feed base (5). A square piece (18) is provided at a lower end of a raising and lowering link (15) of the vertical drive unit (9). A guide member (19) including a guide groove (20) configured to guide the square piece (18) is disposed right under the feed base (5). An upper end of the raising and lowering link (15) is connected to a part of the feed base (5) between the swinging shaft (6) and the feed dog (3).

Provided is a sewing machine that can be reduced in size by employing a simple configuration for a feed dog drive device. A lateral feed drive unit (8) and a vertical drive unit (9) transmit rotation of a drive shaft (7) to a feed dog (3). The feed dog (3) is supported by a swingable feed base (5). A square piece (18) is provided at a lower end of a raising and lowering link (15) of the vertical drive unit (9). A guide member (19) including a guide groove (20) configured to guide the square piece (18) is disposed right under the feed base (5). An upper end of the raising and lowering link (15) is connected to a part of the feed base (5) between the swinging shaft (6) and the feed dog (3).

A sewing machine includes a needle plate, a bed portion, a first urging member, a first engagement member, a second engagement member, and a lock release mechanism. The bed portion is configured to support the needle plate. The first urging member is provided inside the bed portion and configured to urge the needle plate upward. The first engagement member is provided on the needle plate. The second engagement member is provided inside the bed portion, and is configured to fix the needle plate in a fixed position by being engaged with the first engagement member of the needle plate pressed downward against an urging force of the first urging member. The lock release mechanism is configured to release the engagement of the first engagement member and the second engagement member.

A sewing machine includes a needle plate, a bed portion, a first urging member, a first engagement member, a second engagement member, and a lock release mechanism. The bed portion is configured to support the needle plate. The first urging member is provided inside the bed portion and configured to urge the needle plate upward. The first engagement member is provided on the needle plate. The second engagement member is provided inside the bed portion, and is configured to fix the needle plate in a fixed position by being engaged with the first engagement member of the needle plate pressed downward against an urging force of the first urging member. The lock release mechanism is configured to release the engagement of the first engagement member and the second engagement member.

Provided is a sewing machine capable of positioning feed dogs with a sufficient distance below the upper surface of a throat plate when the feed dogs are retracted. Feed dogs 3 protrude and retract from a throat plate 1. A horizontal feed drive unit 8 converts the rotation of a drive shaft 7 into a reciprocating motion in the horizontal direction and transmits the horizontal reciprocating motion to the feed dogs 3. A vertical drive unit 9 converts the rotation of the drive shaft 7 into a reciprocating motion in the vertical direction and transmits the vertical reciprocating motion to the feed dogs 3. A vertical position changing part moves turn-back points P at both ends of a forward path and a return path when the feed dogs 3 reciprocate in the horizontal direction below the throat plate 1.

In feed dog mounting/unmounting mechanism, lever is slidably provided to feed base in the front-rear direction, and is forced backward by a lever force-applying spring. Upon sliding lever rearward, fixing target portion of feed dog 22 is fixedly held by base-side fixing portion of feed base and lever-side fixing portion of lever arranged in the front-rear direction. Stopper is provided to feed base so as to be movable in the upper-lower direction, and holds lever. When feed dog is mounted, stopper is pressed downward by feed dog, which moves stopper so as to allow lever to slide. With this, lever is slid due to force applied by the lever force-applying spring, thereby allowing fixing target portion to be held, interposed between base-side fixing portion and lever-side fixing portion.

In feed dog mounting/unmounting mechanism, lever is slidably provided to feed base in the front-rear direction, and is forced backward by a lever force-applying spring. Upon sliding lever rearward, fixing target portion of feed dog 22 is fixedly held by base-side fixing portion of feed base and lever-side fixing portion of lever arranged in the front-rear direction. Stopper is provided to feed base so as to be movable in the upper-lower direction, and holds lever. When feed dog is mounted, stopper is pressed downward by feed dog, which moves stopper so as to allow lever to slide. With this, lever is slid due to force applied by the lever force-applying spring, thereby allowing fixing target portion to be held, interposed between base-side fixing portion and lever-side fixing portion.

A sewing machine comprises a crank shaft, a first drive shaft, a second drive shaft, a needle assembly, a presser foot, and an upper walking foot. A first crank arm assembly is connected to the crank shaft to the first drive shaft. A first linkage assembly is connected to the first drive shaft to the needle assembly. A second crank arm assembly is connected to the first drive shaft to the second drive shaft. A second linkage assembly is connected to the second drive shaft to the presser foot and the upper walking foot. The second linkage assembly is configured to cause out-of-phase reciprocatory movement of the presser foot and the upper walking foot. The second crank arm assembly has a variable length that is selectably adjustable by an operator to yield at least first and second different stepping heights of the upper walking foot.

A sewing machine includes a support surface for two plies of material to be sewn together and a sewing mechanism that is attached to the support surface and is in operative connection with a machine controller, wherein a plate element positioned between the two material plies is arranged in the material feed area thereof. A vertical adjustment device for the plate element that is actuatable by the machine controller adjusts a vertical distance between the support surface and the plate element, and thus also influences the feed of material to the sewing mechanism. The vertical adjustment device is equipped with an electromagnet for adjusting the position of the plate element. The plate element is equipped with a magnet, which cooperates with the electromagnet.