Embroidery frame

1. An embroidery frame provided with an upper frame, a lower frame that clamps a workpiece cloth with the upper frame, a hinge openably linking the upper and lower frames, and a clamping unit that presses the upper frame to the lower frame, the embroidery frame comprising;

an auxiliary frame which, on a part of an upper end thereof, is provided with a flange and which is fitted in an inner side of the upper frame so as to downwardly press the workpiece cloth clamped between the upper and lower frames; and

an engagement regulating member which is provided on the upper frame and which is engaged to the flange so as to regulate the upward movement of the auxiliary frame.

2. The embroidery frame according to claim 1 , further comprising a plurality of flanges and engagement regulating members.

3. The embroidery frame according to claim 1 , wherein engagement and disengagement of the flange and the engagement regulating members are switchable by rotating the auxiliary frame fitted in the upper frame by a predetermined angle in a circumferential direction with respect to the upper frame.

4. The embroidery frame according to claim 3 , wherein the auxiliary frame has tabs for rotating the auxiliary frame in the circumferential direction.

5. The embroidery frame according to claim 1 , wherein the engagement regulating member is constructed by an elastic member that presses the flange from above when the auxiliary frame is engaged to the upper frame.

6. The embroidery frame according to claim 1 , wherein the upper frame has an outer peripheral portion formed with an annular groove, and a retaining member which is made of metallic material in a substantially annular form is attached on the annular groove, and wherein the hinge which is rotatably supported by the lower frame is formed on a base end of the retaining member and a clamped portion which is clamped by a clamp unit is formed on a fore-end of the retaining member.

7. An embroidery frame provided with an upper frame, a lower frame that clamps a workpiece cloth with the upper frame, a hinge openably linking the upper and lower frames, and a clamping unit that presses the upper frame to the lower frame, the embroidery frame comprising;

an auxiliary frame which is fitted in an inner side of the upper frame and which downwardly presses the workpiece cloth clamped between the upper and lower frames; and

an engagement mechanism in which engagement and disengagement of the upper frame and the auxiliary frame is switchable by rotating the auxiliary frame fitted in the upper frame by a predetermined angle in the circumferential direction with respect to the upper frame; and in which the auxiliary frame is capable of adjusting the pressure applied to press the workpiece cloth.

8. The embroidery frame according to claim 7 , wherein the engagement mechanism is provided with a spiral projection formed on an outer peripheral portion of the auxiliary frame and a spiral groove which is formed in the inner periphery portion of the upper frame and which engages with the spiral projection.

9. The embroidery frame according to claim 7 , wherein the auxiliary frame has a tab for rotating the auxiliary frame in the circumferential direction.

10. The embroidery frame according to claim 7 , wherein the upper frame has an outer peripheral portion formed with an annular groove, and a retaining member which is made of metallic material in a substantially annular form is attached on the annular groove, and wherein the hinge which is rotatably supported by the lower frame is formed on a base end of the retaining member and a clamped portion which is clamped by a clamp unit is formed on a fore-end of the retaining member.

11. An embroidery frame provided with an upper frame, a lower frame that clamps a workpiece cloth with the upper frame, a hinge openably linking the upper and lower frames, and the clamping unit that presses the upper frame to the lower frame, the embroidery frame comprising;

an auxiliary frame which is fitted in an inner side of the upper frame and which downwardly presses the workpiece cloth clamped between the upper and lower frames;

a regulating mechanism that regulates the upward movement of the auxiliary frame with respect to the upper frame, the auxiliary frame being fitted in the upper frame;

a projection which is formed on either one of an upper surface of the lower frame or a lower surface of the upper frame and which has, on an outer peripheral portion thereof, a plurality of notched recesses; and

a groove which is formed on the other of the upper surface of the lower frame or the lower surface of the upper frame and which has, on an outer peripheral portion thereof, a projection that is fitted with the groove when the upper and lower frames are closed.