A control structure for a window covering includes a base, a revolving wheel having an axial post, a restriction means including a bushing fitting around the axial post, a transmission member provided on a side of the bushing, and at least one pawl connected to the axial post. The revolving wheel is connected to the base. The restriction means has at least one cutting groove. The transmission member has at least one abutting portion on an inner wall thereof. The pawl is pivotable within a width of the cutting groove. When the revolving wheel is rotated forward, an end of the pawl passes through the cutting groove to mesh with the abutting portion. When the revolving wheel is rotated backward, the pawl disengages from the abutting portion, and the transmission member is rotatable relative to the revolving wheel. Whereby, it could prevent generating noise while operating the window covering.

A control structure for a window covering includes a base, a revolving wheel having an axial post, a restriction means including a bushing fitting around the axial post, a transmission member provided on a side of the bushing, and at least one pawl connected to the axial post. The revolving wheel is connected to the base. The restriction means has at least one cutting groove. The transmission member has at least one abutting portion on an inner wall thereof. The pawl is pivotable within a width of the cutting groove. When the revolving wheel is rotated forward, an end of the pawl passes through the cutting groove to mesh with the abutting portion. When the revolving wheel is rotated backward, the pawl disengages from the abutting portion, and the transmission member is rotatable relative to the revolving wheel. Whereby, it could prevent generating noise while operating the window covering.

A drive transmission device disclosed. The device has an input gear configured to rotate by a driving force from a driving source; a swing gear configured to rotate by a driving force from the input gear, the swing gear being located at a first position when the input gear is rotated in a forward direction and located at a second position that is different from the first position when the input gear is rotated in a backward direction that is a direction opposite to the forward direction; an output gear configured to separate from the swing gear when the swing gear is located at the first position, and that is in contact with the swing gear to be rotated by rotation of the swing gear when the swing gear is located at the second position; and a shaft portion configured to support the swing gear such that the swing gear is movable between the first position and the second position. The swing gear has a guide hole into which the shaft portion is inserted.

A drive transmission device disclosed. The device has an input gear configured to rotate by a driving force from a driving source; a swing gear configured to rotate by a driving force from the input gear, the swing gear being located at a first position when the input gear is rotated in a forward direction and located at a second position that is different from the first position when the input gear is rotated in a backward direction that is a direction opposite to the forward direction; an output gear configured to separate from the swing gear when the swing gear is located at the first position, and that is in contact with the swing gear to be rotated by rotation of the swing gear when the swing gear is located at the second position; and a shaft portion configured to support the swing gear such that the swing gear is movable between the first position and the second position. The swing gear has a guide hole into which the shaft portion is inserted.

The device comprises a shaft 4, a notched mobile memberfor example a wheel 1and at least three arms 2.1, 2.2, 2.3 that together transmit movement between the shaft 4 and the mobile member. Each arm is hinged to two eccentric bearings 3, 3 that hold same parallel to said arm, regardless of the rotational angle of the shaft 4 with which they rotate synchronously. Each arm engages with the notches of the wheel 1 during at least a portion of the cyclic motion of same, by means of at least one tooth 7 of the arm, in such a way as to ensure mutual displacement. The bearings 3, 3 are arranged such that at least one of the arms engages with the mobile member, regardless of the rotational angle of the shaft 4. Said device can be used for producing low-clearance speed reducers.

The device comprises a shaft 4, a notched mobile memberfor example a wheel 1and at least three arms 2.1, 2.2, 2.3 that together transmit movement between the shaft 4 and the mobile member. Each arm is hinged to two eccentric bearings 3, 3 that hold same parallel to said arm, regardless of the rotational angle of the shaft 4 with which they rotate synchronously. Each arm engages with the notches of the wheel 1 during at least a portion of the cyclic motion of same, by means of at least one tooth 7 of the arm, in such a way as to ensure mutual displacement. The bearings 3, 3 are arranged such that at least one of the arms engages with the mobile member, regardless of the rotational angle of the shaft 4. Said device can be used for producing low-clearance speed reducers.

To provide a drive force transmission device that is capable of transmitting elastic energy of an elastic member to an output shaft with a simpler structure than the structure of the related art. A drive force transmission device includes a first shaft (input shaft), and a second shaft (a crankshaft, a crank disc, an intermediate shaft). A force is applied to the second shaft in a predetermined direction of rotation and in a direction opposite to the direction of rotation. The force varies in strength in association with the rotation. The first shaft is connected to the second shaft, and transmission of a drive force of the first shaft to the second shaft is enabled.

A mounting assembly may include an arced connecting member that includes a first drive chain along a bottom surface of the arced connecting member, a second drive chain positioned adjacent to the first drive chain, and a third drive chain in a gap between the first and the second drive chains. The mounting assembly may include an intermittent-motion drive system that has a drive wheel with a nub extending from a lateral surface of the drive wheel, the nub being shaped to interface with notches included along the third drive chain. The intermittent-motion drive system may include a first and a second protrusion shaped to interface with surfaces of the first and second drive chains, respectively. Rotation of a drive axle extending through the drive wheel may affect rotation of the drive wheel, rotational movement of the nub extending from the drive wheel, and movement of the arced connecting member.

A mounting assembly may include an arced connecting member that includes a first drive chain along a bottom surface of the arced connecting member, a second drive chain positioned adjacent to the first drive chain, and a third drive chain in a gap between the first and the second drive chains. The mounting assembly may include an intermittent-motion drive system that has a drive wheel with a nub extending from a lateral surface of the drive wheel, the nub being shaped to interface with notches included along the third drive chain. The intermittent-motion drive system may include a first and a second protrusion shaped to interface with surfaces of the first and second drive chains, respectively. Rotation of a drive axle extending through the drive wheel may affect rotation of the drive wheel, rotational movement of the nub extending from the drive wheel, and movement of the arced connecting member.

A mounting assembly may include an arced connecting member that includes a first drive chain along a bottom surface of the arced connecting member, a second drive chain positioned adjacent to the first drive chain, and a third drive chain in a gap between the first and the second drive chains. The mounting assembly may include an intermittent-motion drive system that has a drive wheel with a nub extending from a lateral surface of the drive wheel, the nub being shaped to interface with notches included along the third drive chain. The intermittent-motion drive system may include a first and a second protrusion shaped to interface with surfaces of the first and second drive chains, respectively. Rotation of a drive axle extending through the drive wheel may affect rotation of the drive wheel, rotational movement of the nub extending from the drive wheel, and movement of the arced connecting member.