Patent Description:
However, the pressing device in the conventional sewing machine described above requires a complex configuration for changing the pressing force applied by the presser foot to the workpiece.

In view of the foregoing, it is an object of the present invention to provide a pressing device and a sewing machine having a simpler configuration for changing the pressing force that the presser foot applies to a workpiece.

<FIG> illustrates a perspective view of a sewing machine in which a pressing device is mounted.

<FIG> illustrates a front view of a presser bar with the pressing device mounted on the lower end portion thereof, a needle bar mechanism, and a rotary hook mechanism in the sewing machine.

<FIG> illustrates a perspective view of the pressing device on which a presser foot is mounted.

<FIG> illustrates an exploded perspective view of the pressing device and the presser foot.

<FIG> illustrates a cross-sectional view of the pressing device and the presser foot in state F <NUM> in which a first surface portion of a gap-adjusting member is in contact with a contact part of a third member.

<FIG> illustrates a cross-sectional view of the pressing device and the presser foot in state F2 in which a second surface portion of the gap-adjusting member is in contact with the contact part of the third member.

<FIG> illustrates a cross-sectional view of the pressing device and the presser foot in state F3 in which a third surface portion of the gap-adjusting member is in contact with the contact part of the third member.

<FIG> illustrates a cross-sectional view of the pressing device and the presser foot in state F4 in which a fourth surface portion of the gap-adjusting member is in contact with the contact part of the third member.

<FIG> illustrates a front view of the pressing device, the needle bar mechanism, and the rotary hook mechanism in the sewing machine with the bottom end of a needle positioned above a throat plate and the top of a feed dog retracted below the top surface of the throat plate.

<FIG> illustrates a front view of the pressing device, the needle bar mechanism, and the rotary hook mechanism in the sewing machine with the bottom end of the needle positioned above the throat plate and the top of the feed dog positioned above the top surface of the throat plate.

<FIG> illustrates a right-side view of the pressing device, the needle bar mechanism, and the rotary hook mechanism in the sewing machine with the bottom end of the needle positioned above a throat plate and the top of a feed dog retracted below the top surface of the throat plate.

<FIG> illustrates a right-side view of the pressing device, the needle bar mechanism, and the rotary hook mechanism in the sewing machine with the bottom end of the needle positioned above the throat plate and the top of the feed dog positioned above the top surface of the throat plate.

<FIG> is an explanatory diagram illustrating a position of a needle bar in an up-down direction, a position of the feeding dog in the up-down direction, a position of a presser bar clamp in the up-down direction, a pressure force applied to a workpiece from the presser foot, and a gap between a second member and the third member in the up-down direction as the rotational angle of a sewing machine motor changes in the sewing machine.

<FIG> illustrates a cross-sectional view of the presser bar and the pressing device on which the presser foot is mounted and in which the third surface portion of the gap-adjusting member is in contact with the contact part of the third member, the second member is in a second position relative to a first member, and an urging force of a presser bar spring is not transmitted to the presser foot.

<FIG> illustrates a cross-sectional view of the presser bar and the pressing device on which the presser foot is mounted and in which the third surface portion of the gap-adjusting member is in contact with the contact part of the third member, the second member is in a first position relative to a first member, and an urging force of a presser bar spring is transmitted to the presser foot.

<FIG> illustrates a perspective view of a pressing device according to a first variation on which a presser foot is mounted.

<FIG> illustrates a cross-sectional view of the pressing device and the presser foot in state F5 in which the top of a feed dog is positioned above the top surface of a throat plate and a workpiece is not arranged between the presser foot and the throat plate.

<FIG> illustrates a cross-sectional view of the pressing device and the presser foot in state F6 in which the top of the feed dog is positioned above the top surface of the throat plate and a workpiece is not arranged between the presser foot and the throat plate.

<FIG> illustrates a perspective view of a pressing device according to a second variation on which a presser foot is mounted.

<FIG> illustrates an exploded perspective view of the pressing device and the presser foot illustrated in <FIG>.

Next, an embodiment of the present disclosure will be described while referring to the accompanying drawings. The physical configuration of a sewing machine <NUM> provided with a pressing device <NUM> will be described with reference to <FIG> and <FIG>. The pressing device <NUM> of the present embodiment can sew curved lines and can easily switch between curved line sewing and normal sewing. Directions upward, downward, toward the lower-right, toward the upper-left, toward the lower-left, and toward the upper-right in <FIG> will indicate the top, bottom, right, left, front, and rear sides of the sewing machine <NUM> in which the pressing device <NUM> is mounted. The longitudinal directions of a bed section <NUM> and an arm section <NUM> are aligned with the left-right direction of the sewing machine <NUM>. The side of the sewing machine <NUM> in which a column section <NUM> is arranged constitutes the right side of the sewing machine <NUM>. The direction in which the column section <NUM> extends is the up-down direction relative to the sewing machine <NUM>.

As illustrated in <FIG> and <FIG>, the sewing machine <NUM> includes the bed section <NUM>, the column section <NUM>, the arm section <NUM>, and a head section <NUM>. The bed section <NUM> is the base portion of the sewing machine <NUM> that extends in the left-right direction. The bed section <NUM> includes a throat plate <NUM> provided on the top surface thereof. Beneath the throat plate <NUM>, the bed section <NUM> includes a rotary hook mechanism <NUM>, a feed dog <NUM>, a feed mechanism <NUM>, and a feed dog drop mechanism <NUM>. The rotary hook mechanism <NUM> includes a lower shaft <NUM>, and a horizontal rotary hook <NUM>. The horizontal rotary hook <NUM> rotates along with the rotation of the lower shaft <NUM> to loop a needle thread (not illustrated) around a bobbin thread (not illustrated) beneath the throat plate <NUM>. The throat plate <NUM> has a plate-like shape that extends horizontally. The throat plate <NUM> is formed with a needle hole <NUM> through which a needle <NUM> passes, and slits <NUM> extending in the front-rear direction.

The feed dog <NUM> retractably emerges from the slits <NUM> formed in the throat plate <NUM> for feeding a workpiece C placed on the throat plate <NUM> (see <FIG>). When driven by a sewing machine motor <NUM> described below, the feed mechanism <NUM> drives the feed dog <NUM> to convey the workpiece C rearward or forward. The feed dog drop mechanism <NUM> is configured to move only the feed dog <NUM> below the throat plate <NUM> independently from the drive of the sewing machine motor <NUM>. The user operates a touchscreen <NUM> described below to input instructions for moving the feed dog <NUM> to a prescribed position with the feed dog drop mechanism <NUM>. On the basis of these instructions, the sewing machine <NUM> can control a drive force of the feed dog drop mechanism <NUM> to change the position of the feed dog <NUM> independently from the drive of the sewing machine motor <NUM>.

The column section <NUM> is erected upward from the right end portion of the bed section <NUM>. The sewing machine motor <NUM> is provided inside the upper portion of the column section <NUM>. A liquid crystal display (LCD) <NUM> is provided on the front surface of the column section <NUM>. The touchscreen <NUM> is provided over the front surface of the LCD <NUM>. A pulley <NUM> is provided on the right surface of the column section <NUM>.

The arm section <NUM> extends leftward from the upper end of the column section <NUM> parallel to the bed section <NUM>. The head section <NUM> is coupled with the left end portion of the arm section <NUM>. Provided in the head section <NUM> are a needle bar <NUM>, a needle bar mechanism <NUM>, a threading mechanism <NUM>, a presser bar <NUM>, and the like. A needle clamp <NUM> is fixed to the lower end portion of the needle bar <NUM>. The needle <NUM> is detachably fixed by the needle clamp <NUM>. The needle <NUM> can be mounted on the lower end portion of the needle bar <NUM> via the needle clamp <NUM>.

The needle bar mechanism <NUM> includes the sewing machine motor <NUM>, a spindle <NUM>, a link mechanism <NUM>, and a needle bar clamp <NUM>. The spindle <NUM> rotates in response to the drive of the sewing machine motor <NUM> to transmit the drive of the sewing machine motor <NUM> to the needle bar <NUM> via the link mechanism <NUM> and needle bar clamp <NUM> illustrated in <FIG>. The needle bar clamp <NUM> is fixed to the needle bar <NUM>. The needle bar mechanism <NUM> moves the needle bar <NUM> in the up-down direction in response to the drive of the sewing machine motor <NUM>. The spindle <NUM> also rotates when the user rotates the pulley <NUM>. The threading mechanism <NUM> is configured to pass the needle thread through an eye (not illustrated) of the needle <NUM>.

As illustrated in <FIG>, the presser bar <NUM> extends in the up-down direction on the rear side of the needle bar <NUM>. The presser bar <NUM> moves in the up-down direction in synchronization with the drive of the sewing machine motor <NUM>, and more specifically in synchronization with the drive of the feed dog <NUM>. Provided at the presser bar <NUM> are a presser bar spring <NUM>, a presser bar clamp <NUM>, and a lever <NUM>. The presser bar spring <NUM> urges the presser bar <NUM> downward. The presser bar spring <NUM> is a coil spring placed around the presser bar <NUM>. The presser bar clamp <NUM> is fixed to the presser bar <NUM> and contacts the lower end of the presser bar spring <NUM> to define the position of the lower end of the presser bar spring <NUM>.

The lever <NUM> switches the position of the presser bar <NUM> in the up-down direction by being manually operated. The lever <NUM> includes a shaft <NUM>, protrusions <NUM> and <NUM>, a contact part <NUM>, and an operating part <NUM>. The shaft <NUM> is provided inside the head section <NUM>. The protrusions <NUM> and <NUM> are portions of the lever <NUM> near the shaft <NUM> that protrude away from the shaft <NUM>. The contact part <NUM> is a convex part disposed on the periphery of the shaft <NUM> to the left of the protrusion <NUM> and protrudes away from the shaft <NUM>.

The operating part <NUM> is the portion of the lever <NUM> farthest from the shaft <NUM>. By operating the operating part <NUM> with a finger or other actuator, the user can rotate the lever <NUM> clockwise or counterclockwise in a front view about the shaft <NUM> in order to switch the presser bar <NUM> between a raised position and a lowered position. <FIG> illustrates a state in which the operating part <NUM> is below the shaft <NUM> and the presser bar <NUM> is in the lowered position. When the presser bar <NUM> is in the lowered position, the contact part <NUM> is positioned above the shaft <NUM>.

If the operating part <NUM> is rotated counterclockwise in a front view from the state in <FIG> until the operating part <NUM> is positioned on the lower right of the shaft <NUM>, the protrusion <NUM> of the lever <NUM> contacts a bottom surface <NUM> of the presser bar clamp <NUM>, moving the presser bar <NUM> to the raised position. When the presser bar <NUM> is in the raised position, a portion of the lever <NUM> between the protrusion <NUM> and protrusion <NUM> contacts the bottom surface <NUM> of the presser bar clamp <NUM>. The user performs operations for placing or retrieving a workpiece C while the presser bar <NUM> is in the raised position.

The sewing machine <NUM> allows either the pressing device <NUM> or a conventional pressing device to be detachably mounted on the lower end portion of the presser bar <NUM>. When a conventional pressing device is mounted on the presser bar <NUM> and the presser bar <NUM> is in the lowered position, a presser foot <NUM> described below contacts the workpiece C on the throat plate <NUM> and presses the workpiece C downward. When a conventional pressing device is mounted on the presser bar <NUM>, the presser bar clamp <NUM> coupled with the presser bar <NUM> in the sewing machine <NUM> does not contact the lever <NUM> of the sewing machine <NUM> as the needle bar <NUM> reciprocates in the up-down direction (i.e., moves upward and downward).

In other words, when a conventional pressing device is mounted on the presser bar <NUM> and the presser bar <NUM> is in the lowered position, the presser bar clamp <NUM> is spaced apart from the lever <NUM> while the needle bar <NUM> of the sewing machine <NUM> reciprocates in the up-down direction (i.e., moves upward and downward) so that the urging force of the presser bar spring <NUM> is constantly transmitted to the presser foot <NUM>. On the other hand, when the pressing device <NUM> of the present embodiment is mounted on the presser bar <NUM> and the presser bar <NUM> is in the lowered position, the pressing device <NUM> can switch whether the urging force of the presser bar spring <NUM> is constantly transmitted to the presser foot <NUM> or not while the needle bar <NUM> reciprocates in the up-down direction (i.e., moves upward and downward).

As illustrated in <FIG> and <FIG>, the presser foot <NUM> includes a main portion <NUM> having a plate-like shape that is rectangular in a plan view and is elongated in the front-rear direction. Both the front end portion and rear end portion of the main portion <NUM> are curved upward. The main portion <NUM> is formed with a notch <NUM> in the front portion thereof. The main portion <NUM> is formed with a notch <NUM> in the rear portion thereof.

In a plan view, the notch <NUM> is formed in an R-shape along a left-right center M of the main portion <NUM> and extends rearward from the front edge of the main portion <NUM>. When the pressing device <NUM> that supports the presser foot <NUM> is mounted on the lower end portion of the presser bar <NUM> and the sewing machine <NUM> is driven, the needle <NUM> passes through the rear portion of the notch <NUM>. In a plan view, the notch <NUM> is formed in a rectangular shape along the left-right center M of the main portion <NUM> and extends forward from the rear edge of the main portion <NUM> of the presser foot <NUM>.

The presser foot <NUM> also includes a pair of shaft supports <NUM>, and a shaft <NUM> extending in the left-right direction. The shaft supports <NUM> are parts protruding upward from the top surface of the main portion <NUM> at positions rearward of the notch <NUM> and forward of the notch <NUM>. The shaft supports <NUM> extend in the front-rear direction and are spaced apart from each other in the left-right direction. Each of the shaft supports <NUM> is formed with a hole <NUM> penetrating therethrough in the left-right direction. While inserted into the holes <NUM>, the shaft <NUM> is held by the shaft supports <NUM>.

As illustrated in <FIG> and <FIG>, the pressing device <NUM> includes a first member <NUM>, a second member <NUM>, a third member <NUM>, a gap-adjusting member <NUM>, an urging member <NUM>, a guide part <NUM>, a restricting part <NUM>, and a shaft part <NUM>. The first member <NUM> has a mounting part <NUM> that is mounted on the presser bar <NUM> of the sewing machine <NUM>. While the mounting part <NUM> is mounted on the presser bar <NUM>, the first member <NUM> moves in the up-down direction along with the presser bar <NUM> which is urged downward. Hereinafter, a state in which the mounting part <NUM> of the first member <NUM> is mounted on the presser bar <NUM>, i.e., a state in which the pressing device <NUM> is mounted in the sewing machine <NUM> will be also called a mounted state.

The first member <NUM> further includes a main portion <NUM>, and a front portion <NUM>. The main portion <NUM> is a portion having a C-shape in a plan view with the mounting part <NUM> recessed leftward from the right side thereof. The left side of the main portion <NUM> is formed with a circular hole <NUM> that penetrates the same in the left-right direction and is in communication with the mounting part <NUM>. The circular hole <NUM> is circular in a side view. The main portion <NUM> is formed with an insertion hole <NUM> to the rear of the mounting part <NUM>. The insertion hole <NUM> penetrates the main portion <NUM> in the up-down direction. The front portion <NUM> protrudes forward from the lower portion on the front side of the main portion <NUM>. The front portion <NUM> is formed with an insertion hole <NUM> that penetrates the same in the up-down direction. The insertion hole <NUM> has a circular shape in a plan view. The main portion <NUM> has a support part <NUM> recessed downward and forward from the upper rear portion thereof. The support part <NUM> has a left wall <NUM> and a right wall <NUM>. Each of the left wall <NUM> and right wall <NUM> is formed with an insertion hole <NUM> in the rear portion thereof. Each insertion hole <NUM> penetrates the corresponding left wall <NUM> and right wall <NUM> in the left-right direction. A rotational shaft <NUM> described later is inserted into the insertion holes <NUM>.

The second member <NUM> supports the presser foot <NUM>, which is pressed downward on a workpiece C placed on the bed section <NUM> of the sewing machine <NUM>. The second member <NUM> has a plate-like shape that is rectangular in a plan view. The second member <NUM> includes a main portion <NUM>, a contact part <NUM>, and a front portion <NUM>. The main portion <NUM> has a horizontal plate-like shape elongated in the front-rear direction. The length of the main portion <NUM> of the second member <NUM> in the up-down direction is smaller than the length of the first member <NUM> in the up-down direction. The main portion <NUM> is formed with a recess <NUM>. The recess <NUM> is a downwardly recessed part in the front-rear center region of the main portion <NUM>.

The guide part <NUM> guides movement of the second member <NUM> relative to the first member <NUM>. The guide part <NUM> is a shaft fixed to the second member <NUM>. The guide part <NUM> has a column-like shape that protrudes upward from the top surface of the main portion <NUM> at a position rearward of the recess <NUM>. The length of the guide part <NUM> in the up-down direction is greater than the length of the main portion <NUM> of the first member <NUM> in the up-down direction. With the urging member <NUM> mounted around the guide part <NUM>, the guide part <NUM> is inserted into an insertion hole <NUM> formed in the third member <NUM> described later. The guide part <NUM> is further inserted into the insertion hole <NUM> formed in the first member <NUM> above a main portion <NUM> described later in which the insertion hole <NUM> is formed. A retaining ring <NUM> is mounted on the top end of the guide part <NUM> after the guide part <NUM> has been inserted through both the first member <NUM> and third member <NUM> in the up-down direction. The retaining ring <NUM> defines the range of movement in the up-down direction for the first member <NUM> relative to the second member <NUM>. By inserting the guide part <NUM> through the insertion hole <NUM> of the first member <NUM>, the insertion hole <NUM> restricts movement in the horizontal direction of the first member <NUM> relative to the second member <NUM>. By inserting the guide part <NUM> through the insertion hole <NUM> of the third member <NUM>, the insertion hole <NUM> restricts movement in the horizontal direction of the third member <NUM> relative to the second member <NUM>.

The contact part <NUM> is a cylindrical protrusion provided to the rear of the recess <NUM>. The contact part <NUM> has a ring-like shape in a plan view and surrounds the guide part <NUM>. The contact part <NUM> protrudes upward from the top surface of the main portion <NUM>.

The urging member <NUM> is a coil spring. As illustrated in <FIG>, the upper end of the urging member <NUM> is in contact with a contact part <NUM> provided in the third member <NUM> described later, while the lower end of the urging member <NUM> is in contact with the contact part <NUM> of the second member <NUM>. In the mounted state where the first member <NUM> is mounted on the presser bar <NUM>, the urging member <NUM> urges the second member <NUM> and third member <NUM> away from each other with an urging force smaller than the pressing force of the presser bar <NUM>, i.e., the urging force of the presser bar spring <NUM>.

The restricting part <NUM> has a column-like shape that protrudes upward from the top surface of the main portion <NUM> at a position forward of the recess <NUM> and rearward of the front portion <NUM>. The restricting part <NUM> extends parallel to the guide part <NUM>. The length of the restricting part <NUM> in the up-down direction is smaller than the length of the guide part <NUM> in the up-down direction. The restricting part <NUM> is inserted through an insertion hole <NUM> formed in the third member <NUM> described later and the insertion hole <NUM> of the first member <NUM>. A retaining ring <NUM> is mounted on the top end of the restricting part <NUM> after the restricting part <NUM> has been inserted through the first member <NUM> and third member <NUM> in the up-down direction. The retaining ring <NUM> defines the range of movement in the up-down direction for the first member <NUM> relative to the second member <NUM>. In the mounted state where the first member <NUM> is mounted on the presser bar <NUM>, the restricting part <NUM> and guide part <NUM> are arranged with the mounting part <NUM> therebetween in the front-rear direction, which crosses the longitudinal direction of the presser bar <NUM>, i.e., the up-down direction. Both the restricting part <NUM> and the guide part <NUM> are fixed to the second member <NUM>.

The front portion <NUM> protrudes forward from the front side of the main portion <NUM>. The front portion <NUM> is formed with a hole <NUM> that penetrates the front portion <NUM> in the left-right direction. When the presser foot <NUM> is being mounted on the second member <NUM>, the second member <NUM> is placed between the pair of shaft supports <NUM> in the presser foot <NUM> in the left-right direction and the shaft <NUM> is inserted through the hole <NUM>. The second member <NUM> supports the presser foot <NUM> to be pivotable around the shaft <NUM>.

The third member <NUM> is disposed between the first member <NUM> and second member <NUM> in the up-down direction. The third member <NUM> includes a main portion <NUM>, and a front plate portion <NUM>. The main portion <NUM> has an inverted L-shape when viewed from the right side. The main portion <NUM> is formed with an insertion hole <NUM> in the upper portion thereof. The insertion hole <NUM> penetrates the main portion <NUM> in the up-down direction. The insertion hole <NUM> has a circular shape in a plan view. The part of the top surface on the main portion <NUM> to the rear of the insertion hole <NUM> is a contact part <NUM> that contacts the gap-adjusting member <NUM>.

The front plate portion <NUM> has a plate-like shape extending forward from the lower-front end of the main portion <NUM>. The front plate portion <NUM> is formed with insertion holes <NUM> and <NUM>. Each of the insertion holes <NUM> and <NUM> penetrates the front plate portion <NUM> in the up-down direction. The insertion hole <NUM> is a circular-shaped hole in a plan view formed in the front portion of the front plate portion <NUM>. The insertion hole <NUM> receives insertion of the restricting part <NUM>. The insertion hole <NUM> is a semicircular hole in a plan view with the convex side on the right and is formed between the insertion hole <NUM> and main portion <NUM>. The presser bar <NUM> is inserted through the insertion hole <NUM>. In a state where the third member <NUM> is arranged above the second member <NUM>, a portion of the recess <NUM> formed in the second member <NUM> is positioned beneath the insertion hole <NUM>.

The gap-adjusting member <NUM> is configured to change the gap between the first member <NUM> and the third member <NUM> by contacting the contact part <NUM> of the third member <NUM>. The gap-adjusting member <NUM> is formed with an insertion hole <NUM> that is elliptical in a side view and penetrates the gap-adjusting member <NUM> in the left-right direction. A rotational shaft <NUM> of the shaft part <NUM> described later is inserted through the insertion hole <NUM> formed in the right wall <NUM>, the insertion hole <NUM>, and the insertion hole <NUM> formed in the left wall <NUM>, and is supported by the support part <NUM> of the first member <NUM> rearward of the insertion hole <NUM> through which the guide part <NUM> is inserted. A retaining ring <NUM> is mounted on the left end portion of the rotational shaft <NUM>.

The gap-adjusting member <NUM> is disposed between the left wall <NUM> and right wall <NUM> of the support part <NUM> in the left-right direction. The gap-adjusting member <NUM> is provided closer to the guide part <NUM> than to the restricting part <NUM>. In other words, the distance in the front-rear direction between the gap-adjusting member <NUM> and restricting part <NUM> is greater than the distance in the front-rear direction between the gap-adjusting member <NUM> and guide part <NUM>. In the mounted state where the pressing device <NUM> is mounted on the lower end portion of the presser bar <NUM>, the guide part <NUM> and gap-adjusting member <NUM> are arranged on the same side of the presser bar <NUM>, i.e., both the guide part <NUM> and gap-adjusting member <NUM> are arranged on the rear side of the presser bar <NUM>. However, the restricting part <NUM> and gap-adjusting member <NUM> are arranged on different sides of the presser bar <NUM>. In other words, the restricting part <NUM> is provided on the front side of the presser bar <NUM> while the gap-adjusting member <NUM> is provided on the rear side of the presser bar <NUM>. In a plane parallel to both the longitudinal direction of the presser bar <NUM>, i.e., the up-down direction, and the front-rear direction, a line connecting the contact point between the gap-adjusting member <NUM> and contact part <NUM> and the axial center of the rotational shaft <NUM> inserted through the insertion hole <NUM> is perpendicular to the contact part <NUM> and parallel to the longitudinal direction of the presser bar <NUM>, i.e., the up-down direction. Therefore, the gap-adjusting member <NUM> will not rotate inadvertently when receiving a force from the presser bar spring <NUM>.

The gap-adjusting member <NUM> in the present embodiment is a cam that can rotate about the rotational shaft <NUM> supported by the first member <NUM> to change the gap between the first member <NUM> and third member <NUM> in multiple steps. The gap-adjusting member <NUM> includes surface portions <NUM> through <NUM>. Each of the surface portions <NUM> through <NUM> has a curved surface that extends parallel to the rotational center of the rotational shaft <NUM>. Each of the surface portions <NUM> through <NUM> is positioned a different distance from the rotational center of the rotational shaft <NUM>. That is, the distance from the rotational center of the rotational shaft <NUM> decreases in order of the surface portions <NUM> through <NUM>. The compressed amount of the urging member <NUM> changes according to the gap between the contact part <NUM> of the second member <NUM> and the contact part <NUM> of the third member <NUM> in the up-down direction.

The shaft part <NUM> includes the rotational shaft <NUM> and a dial <NUM>. The dial <NUM> is provided on one end portion of the rotational shaft <NUM> for rotating the cam (i.e., gap-adjusting member <NUM>). The dial <NUM> is mounted on the right end portion of the rotational shaft <NUM> in the mounted state where the pressing device <NUM> is mounted on the presser bar <NUM>. The radius R1 of the dial <NUM> is larger than the maximum radius R2 of the gap-adjusting member <NUM>. When viewed in a direction parallel to the rotational center of the rotational shaft <NUM>, the gap-adjusting member <NUM> is inside the contour of the dial <NUM>. The dial <NUM> may be provided with graduation markings and the like used to indicate the positions corresponding to the surface portions <NUM> through <NUM> that are to be in contact with the contact part <NUM> of the third member <NUM>.

The state of the pressing device <NUM> changes among states F1 through F4 depending on what surface portion of the gap-adjusting member <NUM> is in contact with the contact part <NUM> of the third member <NUM>, and the position of the third member <NUM> relative to the first member <NUM> in the up-down direction is different for each of these states. The third member <NUM> is in contact with the second member <NUM> in the up-down direction at a transmission time when the urging force of the presser bar spring <NUM> is being transmitted to the presser foot <NUM>. In other words, the top of the feed dog <NUM> in the sewing machine <NUM> is raised above the throat plate <NUM> at the transmission time illustrated in states F1 through F4.

Specifically, state F1 illustrated in <FIG> shows the transmission time while the first surface portion <NUM> of the gap-adjusting member <NUM> is in contact with the contact part <NUM>. In state F1, the gap between the front portion <NUM> of the first member <NUM> and the front plate portion <NUM> of the third member <NUM> in the up-down direction is the largest among states F1 through F4. Additionally, in state F1, the main portion <NUM> of the first member <NUM> is preferably in contact with the retaining ring <NUM> while the front portion <NUM> of the first member <NUM> is preferably in contact with the retaining ring <NUM>, but the first member <NUM> is assembled so that at least the spaced amount (i.e., gap) between either the main portion <NUM> and retaining ring <NUM> or the front portion <NUM> and retaining ring <NUM> in the up-down direction is near zero. That is, in state F1 the second member <NUM> and third member <NUM> are always in contact with each other in the up-down direction so that the urging force of the presser bar spring <NUM> is transmitted to the presser foot <NUM>, regardless of the rise or fall in the feed dog <NUM>. Accordingly, the pressing device <NUM> suppresses rotational movement of the workpiece C such as cloth in the same manner as a conventional pressing device.

State F2 illustrated in <FIG> shows the transmission time while the second surface portion <NUM> of the gap-adjusting member <NUM> is in contact with the contact part <NUM>. In state F2, the gap between the front portion <NUM> of the first member <NUM> and the front plate portion <NUM> of the third member <NUM> in the up-down direction is the second largest among states F1 through F4. Here, the main portion <NUM> of the first member <NUM> is spaced apart from the retaining ring <NUM> in the up-down direction, and the front portion <NUM> of the first member <NUM> is spaced apart from the retaining ring <NUM> in the up-down direction.

State F3 illustrated in <FIG> shows the transmission time while the third surface portion <NUM> of the gap-adjusting member <NUM> is in contact with the contact part <NUM>. In state F3, the gap between the front portion <NUM> of the first member <NUM> and the front plate portion <NUM> of the third member <NUM> in the up-down direction is the third largest among states F1 through F4. Here, the main portion <NUM> of the first member <NUM> is spaced apart from the retaining ring <NUM> in the up-down direction, and the front portion <NUM> of the first member <NUM> is spaced apart from the retaining ring <NUM> in the up-down direction.

State F4 illustrated in <FIG> shows the transmission time while the fourth surface portion <NUM> of the gap-adjusting member <NUM> is in contact with the contact part <NUM>. In state F4, the gap between the front portion <NUM> of the first member <NUM> and the front plate portion <NUM> of the third member <NUM> in the up-down direction is the fourth largest among states F1 through F4, i.e., the smallest among states F1 through F4. Here, the front portion <NUM> of the first member <NUM> is slightly spaced apart from the front plate portion <NUM> of the third member <NUM> in the up-down direction, but the front portion <NUM> of the first member <NUM> may be in contact with the front plate portion <NUM> of the third member <NUM> in the up-down direction. The main portion <NUM> of the first member <NUM> is spaced apart from the retaining ring <NUM> in the up-down direction, and the front portion <NUM> of the first member <NUM> is spaced apart from the retaining ring <NUM> in the up-down direction.

In other words, in states F2 through F4, the main portion <NUM> of the first member <NUM> is spaced apart from the retaining ring <NUM> in the up-down direction, and the front portion <NUM> of the first member <NUM> is spaced apart from the retaining ring <NUM> in the up-down direction. Among all states F1 through F4, the gap between the main portion <NUM> of the first member <NUM> and the retaining ring <NUM> in the up-down direction is the largest in state F4, and the gap between the front portion <NUM> of the first member <NUM> and the retaining ring <NUM> in the up-down direction is the largest in state F4.

The user places the first surface portion <NUM> of the gap-adjusting member <NUM> in contact with the contact part <NUM>, as shown in state F1, when the user would like the urging force of the presser bar spring <NUM> to be constantly transmitted to the presser foot <NUM> while the needle bar <NUM> of the sewing machine <NUM> reciprocates in the up-down direction (i.e., moves upward and downward) in the same manner as a conventional pressing device. When the user would like the urging force of the presser bar spring <NUM> to be transmitted to the presser foot <NUM> only in prescribed periods of time during which the top of the feed dog <NUM> is above the throat plate <NUM> as the needle bar <NUM> reciprocates in the up-down direction and the urging force of the urging member <NUM> rather than the urging force of the presser bar spring <NUM> to be transmitted to the presser foot <NUM> outside of those prescribed periods of the time, the user places one of the surface portions <NUM> through <NUM> of the gap-adjusting member <NUM> in contact with the contact part <NUM>, as shown in states F2 through F4, depending on the thickness of the workpiece C.

In the present embodiment, the second surface portion <NUM> of the gap-adjusting member <NUM> is suitable for workpieces C having a thickness no greater than <NUM>, the third surface portion <NUM> of the gap-adjusting member <NUM> is suitable for workpieces C having a thickness greater than or equal to <NUM> and less than or equal to <NUM>, and the fourth surface portion <NUM> of the gap-adjusting member <NUM> is suitable for workpieces C having a thickness greater than or equal to <NUM> and less than or equal to <NUM>. The amount of change by which the gap-adjusting member <NUM> changes the gap of the third member <NUM> relative to the first member <NUM> in the up-down direction may be modified as needed.

With the pressing device <NUM> mounted on the lower end portion of the presser bar <NUM>, that is in the mounted state of the pressing device <NUM>, the gap-adjusting member <NUM> can adjust the gap between the first member <NUM> and third member <NUM> to change the position of the third member <NUM> in the up-down direction according to the thickness of the workpiece C, so that the presser bar clamp <NUM> coupled with the presser bar <NUM> of the sewing machine <NUM> transitions between a state in which the presser bar clamp <NUM> is in contact with the lever <NUM> and a state in which the presser bar clamp <NUM> is spaced apart from the lever <NUM> during one reciprocal movement of the needle bar <NUM> of the sewing machine <NUM> in the up-down direction. The contact of the presser bar clamp <NUM> with the lever <NUM> causes the lever <NUM> to define the lower end of the range of movement in the up-down direction for the presser bar <NUM>. In this case, the second member <NUM> moves between a first position and a second position relative to the first member <NUM> during one reciprocal movement of the needle bar <NUM> in the up-down direction. The first position of the second member <NUM> is a position in which the pressing force of the presser bar <NUM>, i.e., the urging force of the presser bar spring <NUM>, is transmitted to the presser foot <NUM>. The second position of the second member <NUM> is a position in which the pressing force of the presser bar <NUM> is not transmitted to the presser foot <NUM>.

Specifically, when the third surface portion <NUM> of the gap-adjusting member <NUM> is in contact with the contact part <NUM>, the first position is the position in which the front plate portion <NUM> of the third member <NUM> is in contact with the front portion <NUM> of the second member <NUM>, as illustrated in <FIG>, and the second position is a position in which the front plate portion <NUM> of the third member <NUM> is spaced apart from the front portion <NUM> of the second member <NUM>, as illustrated in <FIG>. The second member <NUM> can also move between the first position and second position relative to the first member <NUM> when the second surface portion <NUM> or fourth surface portion <NUM> of the gap-adjusting member <NUM> is in contact with the contact part <NUM>.

Next, a method of mounting the pressing device <NUM> on the presser bar <NUM> will be described with reference to <FIG> and <FIG>. In response to a user instruction, the sewing machine <NUM> drives the feed dog drop mechanism <NUM> to retract the top of the feed dog <NUM> below the top surface of the throat plate <NUM> while the bottom end of the needle <NUM> is positioned above the throat plate <NUM>. The user screws a screw <NUM> into a threaded hole <NUM> of the presser bar <NUM> (see <FIG>) to mount the first member <NUM> of the pressing device <NUM> on the lower end portion of the presser bar <NUM>. The user operates the dial <NUM> to adjust the position of the third member <NUM> relative to the first member <NUM> in the up-down direction according to the thickness of the workpiece C.

The positions of the presser bar clamp <NUM> and the presser bar <NUM> in the up-down direction change in accordance with the position of the feed dog <NUM> in the up-down direction. By operating the dial <NUM>, the user can switch whether the third member <NUM> is at a position in the up-down direction where the bottom surface <NUM> of the presser bar clamp <NUM> comes into contact with the contact part <NUM> of the lever <NUM> during reciprocal movement of the needle bar <NUM> of the sewing machine <NUM> in the up-down direction so that the lever <NUM> defines the lower end of the range of movement for the presser bar <NUM>. More specifically, after the pressing device <NUM> has been mounted according to the mounting method described above, when the feed dog <NUM> is raised, the presser foot <NUM> is raised accordingly and the second member <NUM> comes into contact with the third member <NUM>. When the feed dog <NUM> is further raised while the second member <NUM> and third member <NUM> are in contact with each other, the presser bar <NUM> moves upward together with the presser bar clamp <NUM>, causing the presser bar clamp <NUM> to be spaced apart from the contact part <NUM> of the lever <NUM>. In other words, the presser bar clamp <NUM> switches between contacting the contact part <NUM> of the lever <NUM> or spaced apart from the contact part <NUM> of the lever <NUM> in accordance with the top position of the feed dog <NUM>.

Here, the second member <NUM> is in the first position during prescribed periods of time when the bottom end of the needle <NUM> is above the throat plate <NUM>, as illustrated in <FIG>, <FIG>, and <FIG>. The prescribed periods of time are periods in which the top of the feed dog <NUM> is positioned above the throat plate <NUM> to cause the presser bar <NUM> to be raised above the feed dog <NUM> through the presser foot <NUM> and pressing device <NUM> and the presser bar clamp <NUM> to be spaced apart from the contact part <NUM> of the lever <NUM>. The prescribed periods of time in the present embodiment are the periods indicated by P1 in <FIG>. In the first position, the second member <NUM> transmits a downwardly pressing force from the presser bar <NUM> to the presser foot <NUM>.

On the other hand, when the bottom end of the needle <NUM> is below the throat plate <NUM>, the second member <NUM> is in the second position, as illustrated in <FIG>. When in the second position, the second member <NUM> does not transmit the pressing force from the presser bar <NUM> to the presser foot <NUM>. When the bottom end of the needle <NUM> is below the throat plate <NUM>, the presser bar <NUM> is not raised by the feed dog <NUM> since the top of the feed dog <NUM> is positioned below the top surface of the throat plate <NUM>. Therefore, the presser bar <NUM> is in a position where the bottom surface <NUM> on the presser bar clamp <NUM> is in contact with the contact part <NUM> of the lever <NUM> and does not drop any lower regardless of the position of the needle bar <NUM> in the up-down direction. In this state, the urging force of the presser bar spring <NUM> is applied to the lever <NUM> and not to the presser foot <NUM> via the pressing device <NUM>, as shown in <FIG>.

In <FIG>, the pressing force applied to the presser foot <NUM> during a period P2 is expressed on the basis of the assumption that the pressing force applied during periods P1 is <NUM>. However, the "PRESSING FORCE TO PRESSER FOOT" indicated in <FIG> ignores minute changes due to displacement of the urging member <NUM> and minute changes due to displacement of the presser bar spring <NUM> accompanying movement of the feed dog <NUM> in the up-down direction. The pressing force applied to the presser foot <NUM> during the period P2 is smaller than the pressing force applied to the presser foot <NUM> during the period P1.

While the feed dog <NUM> moves from the position at which the bottom surface <NUM> of the presser bar clamp <NUM> contacts the contact part <NUM> of the lever <NUM> to the position at which the top of the feed dog <NUM> comes below the throat plate <NUM>, the second member <NUM> is lowered through the urging force of the urging member <NUM> to a position at which the presser foot <NUM> contacts the workpiece C. As a result, the front plate portion <NUM> of the third member <NUM> is spaced apart from the front portion <NUM> of the second member <NUM> in the up-down direction.

In a state where the first member <NUM> is mounted on the presser bar <NUM> of the sewing machine <NUM> and the second member <NUM> is in the second position, the second member <NUM> transmits the urging force of the urging member <NUM> to the presser foot <NUM>. Thus, while the first member <NUM> is mounted on the presser bar <NUM> of the sewing machine <NUM> and the second member <NUM> supports the presser foot <NUM>, the second member <NUM> is disposed in the second position during periods P2 in which the presser bar clamp <NUM> is in contact with the contact part <NUM> of the lever <NUM> and is disposed in the first position during periods P1 in which the presser bar clamp <NUM> is spaced apart from the contact part <NUM> of the lever <NUM>. In other words, the position of the second member <NUM> is switched in accordance with the position of the top of the feed dog <NUM> in the up-down direction.

The following is a description of the results of experiments conducted both when using the pressing device <NUM> of the present embodiment and when using a conventional pressing device to evaluate the ease of changing the orientation of the workpiece C relative to the throat plate <NUM> during sewing. In these evaluation experiments, sixteen evaluators were asked to sew arbitrary circles and curved lines using both the pressing device <NUM> in the present embodiment, whereby the pressing force applied to the presser foot <NUM> changes while the needle bar <NUM> of the sewing machine <NUM> reciprocates in the up-down direction, and the conventional pressing device, and to evaluate the ease of changing the direction of the workpiece C relative to the throat plate <NUM> on a scale of <NUM> to <NUM>. The sewing machine <NUM> used in these experiments was the CP100X manufactured by Brother Industries, Ltd. , with a sewing speed of <NUM> rpm. The pressing force of the presser bar spring <NUM> was approximately <NUM> N, and the urging force of the urging member <NUM> was approximately <NUM> N. When using the conventional pressing device, the presser bar clamp <NUM> did not contact the contact part <NUM> of the lever <NUM> during sewing and the force applied to the workpiece C by the presser foot <NUM> was nearly constant. When using the pressing device <NUM> of the present embodiment, the presser bar clamp <NUM> contacted the contact part <NUM> of the lever <NUM> during sewing, and the pressing force applied to the workpiece C by the presser foot <NUM> during periods P2 in <FIG> was less than that during periods P1.

The average of evaluation values on the ease of sewing curved lines when using the pressing device <NUM> as compared to when using the conventional pressing device was <NUM>, with <NUM> being "good", <NUM> being "somewhat good", <NUM> being "average", <NUM> being "somewhat poor", and <NUM> being "poor". The above results confirm that the pressing device <NUM> of the present embodiment enables the orientation of the workpiece C relative to the throat plate <NUM> to be changed more easily during sewing than the conventional pressing device by transmitting the pressing force of the presser bar spring <NUM> to the presser foot <NUM>, just as the conventional pressing device, when the workpiece C is being conveyed by the feed dogs <NUM>, but applying a lesser force than the conventional pressing device to the presser foot <NUM> during the periods P2 when the needle <NUM> is piercing the workpiece C.

Next, a pressing device <NUM> according to a variation (first variation) of the embodiment will be described with reference to <FIG> and <FIG>. Components in <FIG> and <FIG> that are the same as those in the embodiment described above are designated with the same reference numerals. As illustrated in <FIG> and <FIG>, the pressing device <NUM> includes a first member <NUM>, a second member <NUM>, a third member <NUM>, a gap-adjusting member <NUM>, the urging member <NUM>, a guide part <NUM>, and a restricting part <NUM>.

The first member <NUM> includes a main portion <NUM>, and a front portion <NUM>. The main portion <NUM> has a mounting part <NUM> formed therein. The mounting part <NUM> is recessed leftward from the right side of the main portion <NUM>. The mounting part <NUM> of the first member <NUM> is formed with a hole <NUM> for fixing the first member <NUM> to the lower end portion of the presser bar <NUM> with a screw <NUM> (see <FIG>). The pressing device <NUM> is mounted on the lower end of the presser bar <NUM> with the screw <NUM> inserted through the hole <NUM> according to the same procedure described in the embodiment for mounting the pressing device <NUM>. The hole <NUM> penetrates the left side of the main portion <NUM> and is in communication with the mounting part <NUM>. The main portion <NUM> is formed with an insertion hole <NUM> to the rear of the mounting part <NUM>. The insertion hole <NUM> penetrates the main portion <NUM> in the up-down direction.

The front portion <NUM> has a plate-like shape that protrudes forward from the lower portion on the front side of the main portion <NUM>. The restricting part <NUM> is a columnar-shaped member that is fixed to the front portion <NUM>. The restricting part <NUM> extends downward from the bottom surface of the front portion <NUM>.

As in the embodiment described above, the second member <NUM> supports the presser foot <NUM>. The second member <NUM> has a plate-like shape that is rectangular in a plan view. The second member <NUM> includes a main portion <NUM> and a front portion <NUM>. The main portion <NUM> has a plate-like shape that is elongated in the front-rear direction. The length of the main portion <NUM> in the up-down direction is smaller than the length of the first member <NUM> in the up-down direction. The main portion <NUM> is formed with an insertion hole <NUM> in the rear portion thereof. The insertion hole <NUM> penetrates the main portion <NUM> in the up-down direction. The main portion <NUM> is formed with an insertion hole <NUM> in the front portion thereof. The insertion hole <NUM> penetrates the main portion <NUM> in the up-down direction. The main portion <NUM> is formed with a recess <NUM>. The recess <NUM> is a downwardly recessed part in the front-rear center region of the main portion <NUM>. The recess <NUM> is located forward of the insertion hole <NUM> and rearward of the insertion hole <NUM>.

The guide part <NUM> is a columnar shaft extending in the up-down direction. The guide part <NUM> guides movement of the second member <NUM> relative to the first member <NUM>. The guide part <NUM> is inserted into each of the insertion hole <NUM> in the first member <NUM>, the insertion hole <NUM> in the second member <NUM>, and an insertion hole <NUM> of the third member <NUM> described later. As shown in state F5 illustrated in <FIG> and state F6 illustrated in <FIG>, a retaining ring <NUM> is mounted on the top end of the guide part <NUM> after the guide part <NUM> has been inserted through both the front portion <NUM> of the first member <NUM> and a front plate portion <NUM> of the third member <NUM> described later in the up-down direction. The retaining ring <NUM> defines the range of movement in the up-down direction for the guide part <NUM> relative to the first member <NUM>. A retaining ring <NUM> is mounted on the bottom end of the guide part <NUM>. The retaining ring <NUM> defines the range of movement in the up-down direction for the second member <NUM> relative to the guide part <NUM>. An insertion hole <NUM> formed in the third member <NUM> described later and the recess <NUM> in the second member <NUM> are provided at positions overlapping the mounting part <NUM> in a plan view.

The restricting part <NUM> is a columnar shaft that extends in the up-down direction. The restricting part <NUM> restricts the second member <NUM> from rotating about the guide part <NUM> relative to the first member <NUM>. The restricting part <NUM> is inserted through both the insertion hole <NUM> in the second member <NUM> and an insertion hole <NUM> in the third member <NUM> described later.

The third member <NUM> includes a main portion <NUM> and a front plate portion <NUM>. The main portion <NUM> has a rectangular parallelepiped shape. The main portion <NUM> is formed with an insertion hole <NUM> penetrating therethrough in the up-down direction. With the urging member <NUM> placed around the guide part <NUM>, the guide part <NUM> is inserted into the insertion hole <NUM>. The third member <NUM> receives an urging force from the urging member <NUM> in a direction away from the second member <NUM>, i.e., an upwardly urging force.

The front plate portion <NUM> is a plate-like portion that protrudes forward from the bottom portion on the front side of the main portion <NUM>. The front plate portion <NUM> is formed with insertion holes <NUM> and <NUM> penetrating therethrough in the up-down direction. The insertion hole <NUM> has a semicircular shape in a plan view, with the convex side on the right. The insertion hole <NUM> is a circular-shaped hole in a plan view formed to the front of the insertion hole <NUM>. The restricting part <NUM> is inserted into the insertion hole <NUM>.

The gap-adjusting member <NUM> is configured to change the gap between the first member and third member <NUM> by contacting the third member <NUM>. The gap-adjusting member <NUM> includes a main portion <NUM>, a lever <NUM>, and a dial <NUM>. The main portion <NUM> has a plate-like shape that is rectangular in a plan view. The guide part <NUM> is inserted through and fixed in the main portion <NUM>. The main portion <NUM> rotatably supports the lever <NUM> about a rotational shaft <NUM> that extends in the left-right direction. The lever <NUM> has a protrusion <NUM> provided on the lower-front portion thereof. The protrusion <NUM> is semispherical in shape, with the convex side facing downward. The dial <NUM> is cylindrical in shape and has female threads on the inner circumferential surface thereof. The guide part <NUM> has male threads formed on a portion of the outer circumferential surface thereof in an area above the gap-adjusting member <NUM>. The male threads of the guide part <NUM> is for engaging with the female threads of the dial <NUM>. Hence, when the dial <NUM> is rotated about the guide part <NUM>, the position of the guide part <NUM> relative to the dial <NUM> in the up-down direction changes, causing a change in the position of the main portion <NUM> relative to the first member <NUM> in the up-down direction.

Next, the procedure by which the gap-adjusting member <NUM> changes the gap between the front portion <NUM> of the first member <NUM> and the front plate portion <NUM> of the third member <NUM> in the up-down direction on the condition that the dial <NUM> is spaced apart from the main portion <NUM> in the up-down direction will be described with reference to <FIG>.

The user mounts the pressing device <NUM> on the lower end portion of the presser bar <NUM> with the lever <NUM> in a horizontal orientation. The user then positions the bottom end of the needle <NUM> above the throat plate <NUM>. At this time, the top of the feed dog <NUM> is positioned above the throat plate <NUM>. After arranging a workpiece C between the presser foot <NUM> and throat plate <NUM>, the user operates the dial <NUM> to place the presser foot <NUM> in contact with the workpiece C, as shown in state F5.

Next, the user rotates the lever <NUM> clockwise in a right-side view, as shown in state F6. By rotating the lever <NUM>, the protrusion <NUM> comes into contact with the top surface of the main portion <NUM> in the third member <NUM>, and the third member <NUM> is pressed downward relative to the first member <NUM> against the urging force of the presser bar spring <NUM> along with the second member <NUM>. In this state, the second member <NUM> moves downward relative to the third member <NUM> while the pressing force of the presser bar <NUM> is not being transmitted to the presser foot <NUM>, and the urging force of the urging member <NUM> is transmitted to the presser foot <NUM>.

In the pressing device <NUM> of the first variation, the user can perform operations to adjust the dial <NUM> on the condition that the top of the feed dog <NUM> has been dropped below the top surface of the throat plate <NUM> by the feed dog drop mechanism <NUM>. In this case, the user does not rotate the lever <NUM> clockwise in a right-side view after adjusting the dial <NUM> but leaves the lever <NUM> in its horizontal orientation.

In the embodiment and its first variation, the sewing machine <NUM>, the sewing machine motor <NUM>, the throat plate <NUM>, the feed dog <NUM>, the slits <NUM>, the feed mechanism <NUM>, the presser bar <NUM>, the bed section <NUM>, the needle bar <NUM>, the needle <NUM>, the presser bar spring <NUM>, and the presser bar clamp <NUM> are examples of the sewing machine, the sewing machine motor, the throat plate, the feed dog, the opening, the presser bar spring, and the presser bar clamp of the present disclosure, respectively. The pressing device <NUM> and the pressing device <NUM> are examples of the pressing device of the present disclosure. The urging member <NUM>, the restricting part <NUM>, and the presser foot <NUM> are examples of the urging member, the restricting part, and the presser foot of the present disclosure, respectively. The first member <NUM> and the first member <NUM> are examples of the first member of the present disclosure. The second member <NUM> and the second member <NUM> are examples of the second member of the present disclosure. The third member <NUM> and the third member <NUM> are examples of the third member of the present disclosure. The guide part <NUM> and the guide part <NUM> are examples of the guide part of the present disclosure. The gap-adjusting member <NUM> and the gap-adjusting member <NUM> are examples of the gap-adjusting member of the present disclosure. The rotational shaft <NUM> and the dial <NUM> are examples of the rotational shaft and the dial of the present disclosure, respectively. The insertion hole <NUM> and the insertion hole <NUM> are examples of the first insertion part of the present disclosure. The insertion hole <NUM> and the insertion hole <NUM> are examples of the second insertion part of the present disclosure. The insertion hole <NUM> is an example of the third insertion part of the present disclosure.

The sewing machine <NUM> in the embodiment described above includes the sewing machine motor <NUM>, needle bar <NUM>, throat plate <NUM>, feed dog <NUM>, feed mechanism <NUM>, presser bar <NUM>, and pressing device <NUM>. The needle bar <NUM> extends in the up-down direction and has the lower end portion on which the needle <NUM> is mountable. The needle bar <NUM> is driven by the sewing machine motor <NUM> to move in the up-down direction. The throat plate <NUM> is formed with the needle hole <NUM> and the slits <NUM>. The needle <NUM> passes through the needle hole <NUM> in accordance with movement of the needle bar in the up-down direction. The feed dog <NUM> can emerge from and be retracted beneath the slits <NUM> formed in the throat plate <NUM>, and feeds a workpiece C placed on the throat plate <NUM>. The feed mechanism <NUM> is driven by the sewing machine motor <NUM> to drive the feed dog <NUM>. The presser bar <NUM> extends in the up-down direction and has a lower end portion on which the pressing device <NUM> is mountable. The presser bar <NUM> moves in the up-down direction in synchronization with the drive of the sewing machine motor <NUM>. The pressing device <NUM> includes the first member <NUM>, second member <NUM>, third member <NUM>, gap-adjusting member <NUM>, urging member <NUM>, and guide part <NUM>. The first member <NUM> has the mounting part <NUM> which is mounted on the presser bar <NUM>. In a mounted state in which the pressing device <NUM> is mounted on the presser bar <NUM>, the first member <NUM> moves in the up-down direction along with the presser bar <NUM> which is urged downward. The second member <NUM> supports the presser foot <NUM> that presses the workpiece C placed on the throat plate <NUM> downward. Through the second member, the presser bar applies a pressing force to the presser foot downward. In the mounted state in which the pressing device <NUM> is mounted on the presser bar <NUM>, the third member <NUM> is disposed between the first member <NUM> and second member <NUM> in the longitudinal direction of the presser bar <NUM>, i.e., in the up-down direction, and is capable of moving in the up-down direction. The gap-adjusting member <NUM> can adjust the gap between the first member <NUM> and third member <NUM> by contacting the third member <NUM>. The urging member <NUM> urges the second member <NUM> and third member <NUM> away from each other with an urging force smaller than the pressing force of the presser bar. The guide part guides movement of the second member <NUM> and third member <NUM> relative to the first member <NUM>.

While the pressing device <NUM> of the sewing machine <NUM> is mounted on the presser bar <NUM>, the position of the second member <NUM> relative to the first member <NUM> can be changed according to the position of the presser bar <NUM> in the up-down direction. Thus, in the mounted state, the pressing device <NUM> can change the pressing force that the presser foot <NUM> applies to the workpiece C through a simpler configuration than that of the conventional technology, i.e., without requiring the sewing machine <NUM> to have a complex structure such as a link mechanism or other connecting members.

By providing the pressing device <NUM> with the gap-adjusting member <NUM>, the gap-adjusting member <NUM> can easily change the gap between the first member <NUM> and third member <NUM> after the pressing device <NUM> has been mounted on the presser bar <NUM> of the sewing machine <NUM>. The second member <NUM> contacts the third member <NUM> in the up-down direction when the urging force of the presser bar spring <NUM> is transmitted to the presser foot <NUM>. In other words, the position of the third member <NUM> relative to the first member <NUM> in the up-down direction defines the position of the second member <NUM> relative to the first member <NUM> in the up-down direction while the urging force of the presser bar spring <NUM> is transmitted to the presser foot <NUM>.

The position of the first member <NUM> relative to the presser bar <NUM> in the up-down direction is defined by the circular hole <NUM> through which the screw <NUM> is inserted. Since the pressing device <NUM> includes the gap-adjusting member <NUM>, the gap-adjusting member <NUM> can easily change the gap between the first member <NUM> and third member <NUM>, i.e., the position of the second member <NUM> relative to the presser bar <NUM> in the up-down direction and the position of the presser foot <NUM> supported by the second member <NUM> relative to the presser bar <NUM> in the up-down direction when the urging force of the presser bar spring <NUM> is transmitted to the presser foot <NUM> after the pressing device <NUM> has been mounted on the presser bar <NUM>.

With the pressing device <NUM> mounted on the presser bar <NUM>, i.e., in the mounted state in which the pressing device <NUM> is mounted on the presser bar <NUM>, the gap-adjusting member <NUM> can change the position of the third member <NUM> in the up-down direction so that the presser bar clamp <NUM> coupled with the presser bar <NUM> comes into contact with the lever <NUM> while the needle bar <NUM> of the sewing machine <NUM> reciprocates in the up-down direction to cause the lever <NUM> to define the lower end of the moving range of the presser bar <NUM>. In this case, the second member <NUM> can move between a first position and a second position relative to the first member <NUM> while the needle bar <NUM> of the sewing machine <NUM> reciprocates in the up-down direction. In the first position, the pressing force of the presser bar <NUM> is transmitted to the presser foot <NUM>. In the second position, the pressing force of the presser bar <NUM> is not transmitted to the presser foot <NUM>. Therefore, in the mounted state, the pressing device <NUM> can switch whether the downwardly pressing force from the presser bar <NUM> is transmitted to the presser foot <NUM> supported by the second member <NUM> or not by changing the position of the second member <NUM> relative to the first member <NUM>. After the pressing device <NUM> is mounted on the lower end portion of the presser bar <NUM>, the pressing device <NUM> can easily set the second position with consideration for the thickness of the workpiece C by changing the gap between the first member <NUM> and third member <NUM>.

The guide part <NUM> has a shaft-like shape or a hollow cylindrical shape, and is fixed to the second member <NUM>. The first member <NUM> is formed with the insertion hole <NUM>. When the guide part <NUM> is inserted through the insertion hole <NUM>, the insertion hole <NUM> restricts movement of the second member <NUM> in directions crossing the up-down direction. The third member <NUM> is formed with the insertion hole <NUM>. When the guide part <NUM> is inserted through the insertion hole <NUM>, the insertion hole <NUM> restricts movement of the second member <NUM> in directions crossing the up-down direction. The urging member <NUM> is a coil spring placed around or inserted into the guide part <NUM>. The compressed state of the coil spring is changed by adjusting the gap between the third member <NUM> and first member <NUM> with the gap-adjusting member <NUM>. In the mounted state, the pressing device <NUM> can stably move the second member <NUM> and third member <NUM> relative to the first member <NUM> in the up-down direction through the relatively simple structure of the guide part <NUM> and urging member <NUM>.

The pressing device <NUM> includes the restricting part <NUM>. In the mounted state in which the pressing device <NUM> is mounted on the presser bar <NUM>, the restricting part <NUM> is fixed to the second member <NUM> on the opposite side of the mounting part <NUM> from the guide part <NUM> in a direction perpendicular to the longitudinal direction of the presser bar <NUM>, i.e., a direction perpendicular to the up-down direction. The restricting part <NUM> restricts the second member <NUM> from rotating about the guide part <NUM> relative to the first member <NUM>. The restricting part <NUM> is inserted through the insertion hole <NUM> formed in the first member <NUM>. The gap-adjusting member <NUM> is disposed closer to the guide part <NUM> than to the restricting part <NUM>. The restricting part <NUM> of the pressing device <NUM> can suppress the second member <NUM> from rotating about the guide part <NUM> relative to the first member <NUM>. Since the gap-adjusting member <NUM> is disposed relatively close to the urging member <NUM>, which urges the second member <NUM> and third member <NUM>, the operations for adjusting the gap between the second member <NUM> and third member <NUM> with the gap-adjusting member <NUM> are easier than if the gap-adjusting member <NUM> were disposed closer to the restricting part <NUM> than to the guide part <NUM>.

The gap-adjusting member <NUM> has a cam that can change the gap between the first member <NUM> and third member <NUM> in multiple steps. The urging member <NUM> is a spring whose compressed amount is changed according to this gap. The gap-adjusting member <NUM> of the pressing device <NUM> can change the gap between the second member <NUM> and third member <NUM> through the simple structure of a cam.

The gap-adjusting member <NUM> has a cam that can rotate about the rotational shaft <NUM> supported by the first member <NUM> and can change the gap between the first member <NUM> and third member <NUM> in multiple steps. Since the gap-adjusting member <NUM> of the pressing device <NUM> can rotate about the rotational shaft <NUM>, which is supported by the first member <NUM>, the operations for adjusting the gap between the second member <NUM> and third member <NUM> with the cam can be simplified.

The pressing device <NUM> includes the dial <NUM> for rotating the cam. In the mounted state in which the pressing device <NUM> is mounted on the presser bar <NUM>, the rotational shaft <NUM> extends in a direction perpendicular to the longitudinal direction of the presser bar <NUM>, i.e., the up-down direction, and has an extending end portion on which the dial <NUM> is mounted. The dial <NUM> has a larger radius than the radius of the cam of the gap-adjusting member <NUM>. The dial <NUM> of the pressing device <NUM> can simplify operations for adjusting the gap between the second member <NUM> and third member <NUM> with the cam.

In the mounted state in which the pressing device <NUM> is mounted on the presser bar <NUM>, when the direction that the sewing machine <NUM> conveys the workpiece C is rearward, the rotational shaft <NUM> extends in the left-right direction, and the dial <NUM> is mounted on the right end portion of the rotational shaft <NUM>. The dial <NUM> of the pressing device <NUM> helps simplify operations for adjusting the gap between the second member <NUM> and third member <NUM> with the cam, irrespective of whether the user is right-handed or left-handed.

The sewing machine <NUM> includes the lever <NUM>, presser bar spring <NUM>, and presser bar clamp <NUM>. The lever <NUM> switches the position of the presser bar <NUM> in the up-down direction by being manually operated. The presser bar spring <NUM> urges the presser bar <NUM> downward. The presser bar clamp <NUM> is fixed to the presser bar <NUM> and defines the lower end position of the presser bar spring <NUM>. During prescribed periods of time in which the bottom end of the needle <NUM> is positioned above the throat plate <NUM>, the presser bar clamp <NUM> is spaced apart from the lever <NUM> to cause transmission of the urging force of the presser bar spring <NUM> to the second member <NUM> to be engaged. When the bottom end of the needle <NUM> is positioned beneath the throat plate <NUM>, the presser bar clamp <NUM> contacts the lever <NUM> to cause the transmission of the urging force of the presser bar spring <NUM> to be disengaged. In the mounted state in which the pressing device <NUM> is mounted on the presser bar <NUM>, the pressing device <NUM> can switch whether the downwardly pressing force of the presser bar <NUM> is transmitted to the presser foot <NUM>, which is supported by the second member <NUM>, by changing the position of the second member <NUM> relative to the first member <NUM>. After the pressing device <NUM> has been mounted on the lower end portion of the presser bar <NUM>, the pressing device <NUM> can set the second position of the second member <NUM> with consideration for the thickness of the workpiece C by adjusting the gap between the first member <NUM> and third member <NUM>.

A pressing device <NUM> according to another variation (second variation) of the embodiment will be described with reference to <FIG> and <FIG>. The following description of the present variation simplifies or omits descriptions of structures similar to those in the embodiment illustrated in <FIG> and <FIG> while contrasting <FIG> with <FIG> and <FIG> with <FIG>. The pressing device <NUM> illustrated in <FIG> differs from the pressing device <NUM> illustrated in <FIG> primarily in the arrangement of a restricting part <NUM>, which corresponds to the restricting part <NUM> in <FIG>, and the provision of a pair of gap-adjusting members <NUM>, which correspond to the gap-adjusting member <NUM> in <FIG>.

The pressing device <NUM> includes a first member <NUM>, a second member <NUM>, a third member <NUM>, a pair of gap-adjusting members <NUM>, the shaft part <NUM>, the urging member <NUM>, and a guide part <NUM>. The first member <NUM> illustrated in <FIG> corresponds to the first member <NUM> illustrated in <FIG>. The first member <NUM> includes a main portion <NUM> which is formed with insertion holes <NUM> and <NUM> that penetrate therethrough in the up-down direction, and an insertion hole <NUM> that penetrates therethrough in the left-right direction. The front of the main portion <NUM> is configured of a mounting part <NUM>. The mounting part <NUM> is formed with a circular hole <NUM> penetrating the main portion <NUM> in the left-right direction.

The second member <NUM> corresponds to the second member <NUM> illustrated in <FIG>. The second member <NUM> includes a front portion <NUM>, a step part <NUM>, and a main portion <NUM>. The front portion <NUM> is formed with a hole <NUM> penetrating therethrough in the left-right direction. The step part <NUM> is a part disposed between the front portion <NUM> and main portion <NUM> in the front-rear direction and protruding above the main portion <NUM>. The step part <NUM> is formed with a recess <NUM> recessed downward. The recess <NUM> is positioned below the mounting part <NUM> of the first member <NUM>.

The main portion <NUM> is provided to the rear of the step part <NUM>. The guide part <NUM> and a restricting part <NUM> are fixed to the main portion <NUM>. Each of the guide part <NUM> and restricting part <NUM> has a column-like shape that extends in the up-down direction. A contact part <NUM> is provided on the lower portion of the guide part <NUM>. The contact part <NUM> has a ring-like shape in a plan view and protrudes upward from the top surface of the main portion <NUM>. The restricting part <NUM> is positioned rearward from the recess <NUM> and guide part <NUM>. The length of the restricting part <NUM> in the up-down direction is the same as the length of the guide part <NUM> in the up-down direction.

The third member <NUM> corresponds to the third member <NUM> illustrated in <FIG>. The third member <NUM> includes a main portion <NUM> formed with insertion holes <NUM> and <NUM> that penetrate therethrough in the up-down direction. The main portion <NUM> includes a support base <NUM> having a rectangular shape in a plan view on the upper-front portion thereof. The left edge of the support base <NUM> is positioned on the left side of the insertion hole <NUM> while the right edge of the support base <NUM> is positioned to the right of the insertion hole <NUM>. The area on the top surface of the support base <NUM> to the left-rear of the insertion hole <NUM> is a contact part <NUM> that contacts the left gap-adjusting member <NUM>, while the area on the top surface of the support base <NUM> to the right-rear of the insertion hole <NUM> is a contact part <NUM> that contacts the right gap-adjusting member <NUM>. The support base <NUM> is formed with protrusions <NUM> and <NUM> on the top surface thereof. The protrusion <NUM> protrudes upward in front of the contact part <NUM>, and the protrusion <NUM> protrudes upward in front of the contact part <NUM>. Each of the protrusions <NUM> and <NUM> has a triangular shape in a right-side view. The insertion hole <NUM> is formed between the protrusions <NUM> and <NUM>.

With the urging member <NUM> placed around the guide part <NUM>, the guide part <NUM> is inserted through the insertion hole <NUM> in the third member <NUM> and the insertion hole <NUM> in the first member <NUM>. The bottom end of the urging member <NUM> contacts the contact part <NUM>. A retaining ring <NUM> is mounted on the top end of the guide part <NUM>. The restricting part <NUM> is inserted through the insertion hole <NUM> in the third member <NUM> and the insertion hole <NUM> in the first member <NUM>. A retaining ring <NUM> is mounted on the top end of the restricting part <NUM>. Thus, while the insertion hole <NUM> in which the restricting part <NUM> is inserted is formed forward of the mounting part <NUM> in the first member <NUM> in the embodiment illustrated in <FIG>, the insertion hole <NUM> in which the restricting part <NUM> is inserted is formed rearward of the insertion hole <NUM> which is formed rearward of the mounting part <NUM> and in which the guide part <NUM> is inserted in the first member <NUM> in the second variation illustrated in <FIG>.

The pair of gap-adjusting members <NUM> correspond to the gap-adjusting member <NUM> illustrated in <FIG>. The gap-adjusting members <NUM> are cams that can rotate about the rotational shaft <NUM>, which is supported by the first member <NUM>, to change the gap between the first member <NUM> and third member <NUM> in multiple steps. One gap-adjusting member <NUM> is provided on each of the left and right sides of the main portion <NUM> constituting the first member <NUM>. Each gap-adjusting member <NUM> is formed with an insertion hole <NUM> penetrating therethrough in the left-right direction, and has surface portions <NUM> through <NUM>. While each gap-adjusting member <NUM> in the example illustrated in <FIG> and <FIG> includes surface portions <NUM> through <NUM> for eight steps of adjustment, the surface portions of the gap-adjusting member <NUM> may be designed with any number of steps.

The rotational shaft <NUM> is inserted through the insertion hole <NUM> of each gap-adjusting member <NUM> and the insertion hole <NUM> of the first member <NUM> and is rotatably supported by the first member <NUM>. A retaining ring (not illustrated) is mounted on the left end portion of the rotational shaft <NUM>. The rotational shaft <NUM> is arranged between the restricting part <NUM> and guide part <NUM> in the front-rear direction.

Each of the surface portions <NUM> through <NUM> has a curved surface that extends parallel to the rotational center of the rotational shaft <NUM>. The distance from the rotational center of the rotational shaft <NUM> increases in order of the surface portions <NUM> through <NUM>. Any of the surface portions <NUM> through <NUM> may contact the corresponding contact part <NUM> or <NUM>. As with the pressing device <NUM> of the embodiment, the user changes the gap between the first member <NUM> and third member <NUM> in multiple steps by operating the dial <NUM> in the pressing device <NUM> of the second variation.

In a plane parallel to both the longitudinal direction of the presser bar <NUM>, i.e., the up-down direction, and the front-rear direction, a line connecting the contact point between each of the gap-adjusting member <NUM> and the corresponding contact part <NUM> or <NUM> and the axial center of the rotational shaft <NUM> inserted through the corresponding insertion hole <NUM> is perpendicular to the corresponding contact part <NUM> or <NUM> and parallel to the longitudinal direction of the presser bar <NUM>. Therefore, the gap-adjusting members <NUM> will not rotate inadvertently when receiving a force from the presser bar spring <NUM>. Hence, the pressing device <NUM> cannot change which of the surface portions <NUM> through <NUM> is in contact with the corresponding contact part <NUM> or <NUM> with merely a force against the pressing force applied in the up-down direction.

Further, as the two gap-adjusting members <NUM> rotate about the rotational shaft <NUM>, changing which of the surface portions <NUM> through <NUM> contacts the corresponding contact parts <NUM> and <NUM>, the protrusions <NUM> and <NUM> of the third member <NUM> may contact the corresponding gap-adjusting members <NUM>. When the surface portions <NUM> contact the corresponding contact parts <NUM> and <NUM>, for example, a wall portion <NUM> connecting the surface portions <NUM> and <NUM> in each gap-adjusting member <NUM> contacts the front surface of the corresponding protrusion <NUM> or <NUM>. Each wall portion <NUM> is a surface portion that extends in a direction away from the rotational shaft <NUM>. Through contact with the wall portions <NUM>, the protrusions <NUM> and <NUM> restrict the corresponding gap-adjusting members <NUM> from rotating further counterclockwise in a right-side view from the state in which the surface portions <NUM> are in contact with the corresponding contact parts <NUM> and <NUM>. Hence, the protrusions <NUM> and <NUM> define the end position for the rotation of the gap-adjusting members <NUM>.

In another example, when the surface portions <NUM> contact the corresponding contact parts <NUM> and <NUM>, the surface portions <NUM> are also in contact with the back surfaces of the corresponding protrusions <NUM> and <NUM>. Therefore, when the protrusions <NUM> and <NUM> contact the gap-adjusting members <NUM>, the pressing device <NUM> can better prevent changes in the surface portions <NUM> through <NUM> contacting the contact parts <NUM> and <NUM> caused merely by a force against the pressing force applied in the up-down direction.

When any of the surface portions <NUM> through <NUM> of the gap-adjusting members <NUM> are in contact with the corresponding contact parts <NUM> and <NUM>, the protrusions <NUM> and <NUM> may be spaced apart from or in contact with the corresponding gap-adjusting members <NUM>. The protrusions <NUM> and <NUM> may also function as regulating members that, when in contact with the gap-adjusting members <NUM>, restrict the gap-adjusting members <NUM> from rotating inadvertently.

In the pressing device <NUM> of the second variation described above, the structure in front of the presser bar <NUM> is simpler than that of the pressing device <NUM> of the embodiment when the mounting part <NUM> of the first member <NUM> is mounted on the presser bar <NUM>, providing higher visibility of the workpiece C and the needle <NUM>. Thus, the ease of performing sewing operations is improved over that of the pressing device <NUM> of the embodiment. With the pressing device <NUM>, there is no need to restrict the range in which components extend in the up-down direction in order to ensure the area in front of the presser bar <NUM> is visible, as there is with the restricting part <NUM> of the pressing device <NUM> in the embodiment. Accordingly, since the pressing device <NUM> enables a longer length of the restricting part <NUM> in the up-down direction than that of the restricting part <NUM> of the pressing device <NUM>, the pressing device <NUM> can properly suppress forces that cause the pressing device <NUM> to rotate about the guide part <NUM>. Further, since the pressing device <NUM> provides the restricting part <NUM> to the rear of the presser bar <NUM>, interference between the threading mechanism <NUM> (see <FIG>) and the restricting part <NUM> with respect to the needle <NUM> provided in front of the presser bar <NUM> can be avoided to ensure reliable threading of the needle <NUM>.

In the pressing device <NUM> of the embodiment illustrated in <FIG>, the gap-adjusting member <NUM> is provided between the left wall <NUM> and right wall <NUM> of the first member <NUM>, but the two gap-adjusting members <NUM> are arranged one on either side of the first member <NUM> in the pressing device <NUM> of the second variation illustrated in <FIG>. The pressing device <NUM> can prevent the gap-adjusting members <NUM> from rotating inadvertently and changing the gap between the first member <NUM> and third member <NUM> due to a pressing force acting on the gap-adjusting members <NUM> in the up-down direction.

While the invention has been described in conjunction with various example structures outlined above and illustrated in the figures, the invention is defined by the appended claims. Some specific examples of potential alternatives, modifications, or variations in the embodiments described above are provided below:.

The structures of the sewing machine <NUM> and the pressing device <NUM>, pressing device <NUM>, or pressing device <NUM> may be modified as appropriate. The sewing machine <NUM> may be an industrial sewing machine. The member that the presser bar clamp <NUM> contacts while the needle bar <NUM> of the sewing machine <NUM> reciprocates in the up-down direction may be a member other than the lever <NUM>. The presser bar clamp <NUM> need not contact the lever <NUM> or another member while the needle bar <NUM> of the sewing machine <NUM> reciprocates in the up-down direction. The fixing member that fixes the pressing device <NUM> to the presser bar <NUM> may be modified as needed. For example, a bolt and nut or the like may be used in place of the screw <NUM>. The direction in which the sewing machine <NUM> conveys the workpiece C may be modified as appropriate. The sewing machine <NUM> need not be provided with the feed dog drop mechanism <NUM>. The feed dog drop mechanism <NUM> may be configured to be driven manually.

The guide parts <NUM>, <NUM>, and <NUM> and the restricting parts <NUM>, <NUM>, and <NUM> need not be columnar shaped shafts. The guide part <NUM> and restricting part <NUM> need not both be fixed to the first member <NUM>. The guide part <NUM> may have any configuration for guiding movement of the second member <NUM> and third member <NUM> relative to the first member <NUM>. For example, the guide part <NUM> may be a rail-like part that is fixed to one of the first member <NUM>, second member <NUM>, and third member <NUM> functioning as a fixed member and that engages with a member other than the fixed member of the first member <NUM>, second member <NUM>, and third member <NUM>.

In addition to being shaped as circular holes in a plan view that penetrate the first member <NUM>, <NUM>, and <NUM> in the up-down direction, the insertion holes <NUM>, <NUM>, and <NUM> may be formed in other shapes such as notches formed in the up-down direction. The guide part <NUM> may be a cylinder fixed to the second member <NUM>, and the urging member <NUM> configured as a coil spring may be inserted inside the cylindrical guide part <NUM>. The type, layout, and the like of the urging member <NUM> may be modified as appropriate.

With the pressing device <NUM> mounted on the presser bar <NUM>, i.e., in the mounted state of the pressing device <NUM>, the rotational shaft <NUM> may extend in a direction other than the left-right direction when the direction that the sewing machine <NUM> conveys a workpiece C is rearward. When the rotational shaft <NUM> extends in the left-right direction, the dial <NUM> may be disposed on the left end portion of the rotational shaft <NUM>. When the rotational shaft <NUM> extends in the front-rear direction, the dial <NUM> may be disposed on the rear end portion or front end portion of the rotational shaft <NUM>.

The structure of the gap-adjusting member <NUM> may be modified as needed. The dial <NUM> may have a radius less than or equal to the maximum radius of the gap-adjusting member <NUM>. The gap-adjusting member <NUM> may be capable of rotating about the rotational shaft <NUM> supported by the first member <NUM> for changing the gap between the first member <NUM> and third member <NUM> in two steps or four steps or more. The gap-adjusting member <NUM> may have a curved outer circumference that can change the gap between the first member <NUM> and third member <NUM> linearly. The pressing device <NUM> may include another operating member in place of the dial <NUM>, such as a lever that is coupled to an end portion of the rotational shaft <NUM>, and the rotational shaft <NUM> may be configured to rotate when this operating member is operated.

The method of mounting the pressing device <NUM> in the embodiment may be modified as needed. The pressing device <NUM> may be mounted on the presser bar <NUM> on the condition that the top of the feed dog <NUM> is lower than the top surface of the throat plate <NUM>. In this case, the user first places the workpiece C between the presser foot <NUM> and throat plate <NUM>, then operates the dial <NUM> to place the presser foot <NUM> in contact with the workpiece C, and finally operates the dial <NUM> again to increase the gap to one step larger than the gap corresponding to the thickness of the current workpiece C. When implementing these operations, the amount of thickness variation among each of the surface portions <NUM> through <NUM> must be set smaller than the raised amount of the feed dog <NUM> in the sewing machine <NUM>, for example.

In addition to the gap-adjusting member <NUM>, the pressing device <NUM> of the embodiment may be provided with the gap-adjusting member <NUM> of the first variation. In this case, the user may adjust the gap between the first member <NUM> and third member <NUM> according to the following procedure. The user positions the bottom end of the needle <NUM> above the throat plate <NUM> by placing the needle <NUM> around the top of its range of movement in the up-down direction, and positions the top of the feed dog <NUM> above the throat plate <NUM> by placing the feed dog <NUM> around the top of its range of movement in the up-down direction. After placing a workpiece C between the presser foot <NUM> and throat plate <NUM>, the user adjusts the dial <NUM> to place the presser foot <NUM> in contact with the workpiece C. Finally, the user rotates the lever <NUM> of the gap-adjusting member <NUM> clockwise in a right-side view to increase the gap between the first member <NUM> and third member <NUM>.

The gap-adjusting member <NUM> should contact at least one of the first member <NUM> and third member <NUM>. For example, a plurality of protrusions that protrude upward by different amounts of protrusion may be provided on the contact part <NUM> of the third member <NUM>. With this configuration, the gap between the first member <NUM> and third member <NUM> can be changed in multiple steps by changing which protrusion is contacted by the gap-adjusting member <NUM> supported by the first member <NUM>. Similarly, a plurality of protrusions that protrude downward at different amounts of protrusion may be provided on the bottom surface of the first member <NUM>. In this case, the pressing device <NUM> can change the gap between the first member <NUM> and third member <NUM> in multiple steps by changing which protrusion that the gap-adjusting member <NUM> supported by the third member <NUM> contacts.

The sewing machine <NUM> may include a sensor that detects the thickness of the workpiece C, and a drive mechanism that rotates the rotational shaft <NUM> a prescribed amount through the drive force of a motor. The sewing machine <NUM> may automatically rotate the gap-adjusting member <NUM> about the rotational shaft <NUM> based on the detection value of the sensor. With this configuration, the sewing machine <NUM> can eliminate the user's burden of operating the gap-adjusting members <NUM>, <NUM>, and <NUM>.

Claim 1:
A pressing device (<NUM>, <NUM>, <NUM>) to be mounted in a sewing machine (<NUM>), the sewing machine including: a bed section (<NUM>) on which a workpiece is to be placed; and a presser bar (<NUM>) on which the pressing device is to be mounted, the presser bar extending in an up-down direction and being configured to be urged downward, the pressing device comprising:
a first member (<NUM>, <NUM>, <NUM>) having a mounting part (<NUM>, <NUM>, <NUM>) configured to be mounted on the presser bar, the first member being movable in the up-down direction along with the presser bar in a mounted state in which the pressing device is mounted on the presser bar;
a second member (<NUM>, <NUM>, <NUM>) configured to support a presser foot (<NUM>) configured to press the workpiece placed on the bed section downward, the presser bar being configured to apply, through the second member, a pressing force to the presser foot downward in the mounted state;
characterized in that further comprising:
a third member (<NUM>, <NUM>, <NUM>) disposed between the first member and the second member in the up-down direction in the mounted state, the third member being movable in the up-down direction in the mounted state;
a gap-adjusting member (<NUM>, <NUM>, <NUM>) configured to adjust a gap between the first member and the third member by contacting at least one of the first member and the third member;
an urging member (<NUM>) configured to urge the second member and the third member away from each other with an urging force smaller than the pressing force of the presser bar; and
a guide part (<NUM>, <NUM>, <NUM>) configured to guide movement of the second member and the third member relative to the first member.