Abstract: A spring motor assembly for a Venetian blind includes a bracket formed with confronting insert grooves, a pair of insert plates inserted into the insert grooves, two parallel axles extending transversely between the insert plates, a storage drum mounted rotatably on one of the axles, co-axial and co-rotatable output drum and cord spool mounted rotatably on the other of the axles, and a coil spring extending between the storage drum and the output drum. The bracket is mounted on a top rail of the Venetian blind. The cord spool engages upper ends of two lifting cords of the Venetian blind. The coil spring is wound on at least one of the storage drum and the output drum, and is transferred from one of the drums to the other of the drums when a bottom bar of the Venetian blind is moved upwardly or downwardly relative to the top rail.

Abstract: A cord control device includes a mounting seat mounted removably in a horizontal top housing, from which a plurality of horizontal slats are suspended downwardly one above another. A bottom rail is disposed below the slats. Each of two control cords passes through the top housing and through the slats, and has a first end portion fastened to the bottom rail, and a second end portion which extends out of the top housing. An elongated rack is disposed in a roller-mounting space in the mounting seat. A pair of stationary rollers are journalled in the roller-mounting space one above the other proximate to the elongated rack and are passed slidably over by the second end portions of the control cords, respectively. A movable pinion is disposed movably in the roller-mounting space, and is passed slidably over by the second end portions of the control cords.

Abstract: A mechanism for combining, into a single structure, the functions of raising, lowering and tilting the slats of a Venetian blind. The mechanism is attached to a slat actuating shaft and comprises a hollow positioning tube coupled to the shaft so that axial rotation of tube rotates the shaft and tilts the slats to a desired angle. Slat pull ropes extend into the hollow portion of the tube. The hollow portion of the tube also contains a releasable clamping unit and a stationary roller which is rotatably coupled to the tube. The releasable clamping unit comprises a movable roller and a biasing spring which forces the movable roller toward the stationary roller so that the pull ropes are clamped between the rollers when the slats are raised or lowered to a desired position. An elongated sleeve is mounted on and slidable with respect to the tube.

Abstract: An operating device for a Venetian blind includes a hollow base which is adapted to be disposed in a top housing of the Venetian blind, a locking seat disposed in the hollow base, and a biasing member. The hollow base includes a pair of side plates which form a receiving space therebetween, and a limiting rod which extends transversely between the side plates and which is disposed at a peripheral portion of the receiving space. The hollow base is adapted to permit extension of pull ropes of the Venetian blind into the receiving space. The locking seat is mounted pivotally to the side plates and is disposed in the receiving space on one side of the limiting rod such that the pull ropes are extendible between the locking seat and the limiting rod. The biasing member is mounted on the hollow base and biases the locking seat to pivot toward the limiting rod so that the locking seat is adapted to clamp releasably the pull ropes against the limiting rod.

Abstract: An operating device for a Venetian blind includes a positioning tube coupled to the shaft of the Venetian blind and formed with a top opening and an axially extending slot. An annular stop member is disposed in the receiving space adjacent to the top wall and has an inner surface that confines a tapered central hole which tapers upwardly. A retaining member is axially movable in the positioning tube, and has a tapered upper end portion which complements the tapered central hole and which is extendible into the tapered central hole. A biasing spring biases the retaining member upwardly so that pull ropes which extend through the positioning tube can be clamped between the tapered upper end portion and the stop member. An elongated sleeve is disposed around the positioning tube and is formed with a radial hole that is aligned with the pin hole. An insert pin extends through the radial hole, the slot and the pin hole.

Abstract: An operating device for a Venetian blind includes a rotary tilt control unit which is adapted to be coupled to a shaft of the Venetian blind so as adjust tilting angles of slats. A positioning tube is connected to the tilt control unit and has a top opening and an axially extending slot. A retaining member is axially movable in the positioning tube, and has a tapered upper end portion extendible through the top opening and a radial pin hole aligned with the slot. A biasing spring biases the retaining member upwardly so that pull ropes which extend through the positioning tube can be clamped between the tapered upper end portion and the positioning tube. An elongated sleeve disposed around the positioning tube is formed with a radial hole that is aligned with the pin hole, and is provided with at least one hook projection for hooking end portions of the pull ropes thereon. An insert pin extends through the radial hole, the slot and into the pin hole.