Claims
- 1. An operating device for a Venetian blind which includes an elongated top housing, a horizontally disposed shaft journalled in the top housing, a plurality of horizontal slats suspended one above another from the top housing, each of the slats having two opposite longitudinal sides, a bottom rail disposed below the slats, a pair of pull ropes, each of the pull ropes having a first end which passes through the housing and through the slats and which is mounted to the bottom rail, and a second end which extends out of the housing, and a plurality of pairs of tilting cords disposed on the opposite longitudinal sides of the slats and having upper ends secured to the shaft and lower ends mounted on the bottom rail, said operating device comprising:
- a positioning tube adapted to be coupled to the shaft of the Venetian blind such that axial rotation of said positioning tube results in corresponding axial rotation of the shaft to adjust tilting angles of the slats, said positioning tube having a top wall formed with a top opening and a surrounding wall extending downwardly from a periphery of said top wall, said top wall and said surrounding wall cooperatively confining a receiving space, said top opening being adapted to permit extension of the second ends of the pull ropes through said positioning tube, said surrounding wall having an axially extending slot unit formed therethrough;
- an annular stop member disposed in said receiving space adjacent to said top wall, said stop member having an inner surface that confines a tapered central hole which tapers upwardly and which is aligned with said top opening so as to be adapted to permit extension of the second ends of the pull ropes therethrough;
- a retaining member axially movable in said receiving space of said positioning tube, said retaining member having a tapered upper end portion which complements said tapered central hole of said stop member and which is extendible into said tapered central hole, a pair of axially extending guiding grooves which are adapted to receive the pull ropes, and a radial pin hole aligned with said slot unit, each of said guiding grooves having a section which is located at said tapered end portion of said retaining member and which has a depth not greater than diameter of each of the pull ropes;
- a biasing spring disposed in said positioning tube under said retaining member for biasing said retaining member upwardly so that the pull ropes can be clamped between said tapered upper end portion of said retaining member and said inner surface of said stop member;
- an elongated sleeve disposed around said positioning tube and formed with a radial hole aligned with said pin hole of said retaining member; and
- an insert pin extending through said radial hole of said elongated sleeve, said slot unit of said positioning tube and said pin hole of said retaining member;
- said elongated sleeve being movable downwardly relative to said positioning tube so that said insert pin and said retaining member are moved downwardly against biasing action of said biasing spring together with said elongated sleeve, thereby moving said tapered upper end portion of said retaining member away from said inner surface of said stop member for releasing the pull ropes.
- 2. The operating device according to claim 1, wherein said elongated sleeve has a length sufficient to conceal major portions of the pull ropes that extend out of said positioning tube, said elongated sleeve further having an outer surface provided with at least one hook projection adapted for hooking end portions of the pull ropes that extend out of said elongated sleeve thereon.
- 3. The operating device according to claim 2, further comprising at least one retaining ring which is sleeved on said elongated sleeve and which has said hook projection formed thereon.
- 4. The operating device according to claim 1, wherein said positioning tube has a lower end, said surrounding wall of said positioning tube being formed with an opposite pair of L-shaped retaining slots that extend from said lower end, each of said retaining slots including an axially extending entrance section and a retaining section perpendicular to said entrance section, said operating device further comprising a positioning member disposed at said lower end of said positioning tube and formed with a central opening that is adapted to permit passage of the second ends of the pull ropes therethrough, said positioning member being formed with an opposite pair of engaging protrusions which are extendible into said retaining slots via said entrance sections for retention in said retaining sections, said biasing spring having a lower end abutting against said positioning member.
- 5. The operating device according to claim 4, wherein each of said retaining slots has a resilient retaining projection formed between said entrance section and said retaining section to prevent undesired removal of a respective one of said engaging protrusions from said retaining section.
- 6. The operating device according to claim 4, wherein said positioning member has a lower end formed with a groove which is adapted to engage a tool bit for rotating said positioning member relative to said positioning tube.
- 7. The operating device according to claim 1, further comprising a rotary tilt control unit which is adapted to couple said positioning tube to the shaft of the Venetian blind, said tilt control unit including a tubular connector which is adapted to permit extension of the second ends of the pull ropes therethrough, said tubular connector having a lower end formed with a pair of diametrically opposite first pivot lobes which extend downward and which are formed with first pivot holes, respectively, said positioning tube having an upper end formed with a pair of diametrically opposite second pivot lobes which extend upward and which are formed with second pivot holes, respectively, said tilt control unit further including an annular connector disposed between said lower end of said tubular connector and said upper end of said positioning tube, said annular connector having an opposite pair of first radial protrusions which extend rotatably into said first pivot holes in said first pivot lobes of said tubular connector for connecting pivotally said annular connector to said tubular connector about a first axis, said annular connector further having an opposite pair of second radial protrusions which extend rotatably into said second pivot holes in said second pivot lobes of said positioning tube for connecting pivotally said annular connector to said positioning tube about a second axis perpendicular to said first axis.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part (CIP) of U.S. patent application Ser. No. 08/844,406, filed on Apr. 18, 1997 now U.S. Pat. No. 5,749,405
US Referenced Citations (6)
Continuation in Parts (1)
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Number |
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844406 |
Apr 1997 |
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