Flexible or portable closure – partition – or panel – Plural strip – slat – or panel type – Venetian blind type
Reexamination Certificate
2000-01-06
2001-10-16
Purol, David M. (Department: 3634)
Flexible or portable closure, partition, or panel
Plural strip, slat, or panel type
Venetian blind type
Reexamination Certificate
active
06302182
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to adjustable coverings for architectural openings, and, in particular, to a control drum for the tilt cords of adjustable window coverings in which the friction between the drum and the control shaft can be selectively manipulated.
BACKGROUND OF THE INVENTION
It is known to use adjustable coverings over architectural openings. Such adjustable coverings include cellular panels, Venetian blinds, and many other systems for controlling the passage of light, vision, or air through the architectural openings. For example, cellular panels and Venetian blinds can be adjusted by retracting or extending them, and Venetian blinds may be further adjusted by tilting the slats comprising part of the blind.
Tilter mechanisms for Venetian blinds have been created in a variety of configurations. One such tilter mechanism is described in U.S. Pat. No. 5,341,865 “Fraser et al.”, which is hereby incorporated by reference. As shown therein, a tilter mechanism typically includes a tilt drum (also called a “tilt roll”) that is co-axially mounted on an elongated tilt rod and is adapted to receive the forward and rear ladder laces of the Venetian blind. When the tilt rod is rotated, it rotates the drum in unison therewith, which wraps one of the ladder laces and unwraps the other, thereby causing the slats of the Venetian blind to tilt open and closed about longitudinal/horizontal axes. The tilt rod (and drum) can be rotated by a variety of tilters, including by gear mechanisms driven by a remotely controlled motor or by the manual force of the Venetian-blind user. Tilter mechanisms are also employed to effect adjustment of other adjustable coverings for architectural openings.
In a Venetian blind, the tilter, tilt drum, and tilt rod are all generally located within the headrail housing of the blind (along with other mechanisms such as pulleys and locks to facilitate lifting of the blind). Tilt drum supports are also fixedly attached to the headrail housing to support the tilt drums and/or tilt rod along the length of the headrail. The tilt drum supports prevent the tilt rod from sagging due to the weight of the blind and generally prevent axial movement of the tilt drums relative to the headrail housing.
It is desirable that the tilt rod not be permitted to move axially within the headrail housing. If the tilt rod becomes dislodged from the tilter, for example, the blind cannot be tilted. Moreover, if the tilt rod slides axially within the headrail, it can interfere with other mechanisms, such as the lock for the blind's lifting mechanism. To avoid these problems, the tilt rod can be held in place by a tight connection to the tilter; however, providing a tight fit in the tilter has been found to be cumbersome and difficult during assembly of the blind. Accordingly, the tilt rod is often manufactured in polygonal cross-section that can be slid into a mating, but not tight-fitting, connection in the tilter.
The tilt rod is then held laterally in place by tight fitting connection to the tilt drum. A tight fit between the tilt drum and tilt rod prevents the drum from accidentally sliding relative to the tilt rod. Moreover, because the tilt drums are prohibited from moving laterally by fixed tilt drum supports, the tilt rod can be kept in place without requiring a tight connection to the tilter.
Generally, at least one-half pound of force of interference fit is required between the drum and the tilt rod. Due to manufacturing tolerances, however, the interference-fit force of prior art tilt drums on the tilt rod may be as much as four pounds or more. A high interference-fit force can make it frustrating and difficult to assemble the tilt drum onto the tilt rod.
SUMMARY OF THE INVENTION
The present invention provides a control drum, such as a tilt drum for a Venetian blind, with adjustable friction elements (such as spring legs) so that the friction between the control drum and the control shaft (e.g., tilt rod), can be greatly reduced during installation and then can be greatly increased once the drum has been installed on the control shaft. The present invention accordingly permits easy installation without sacrificing the benefits of an interference fit between the control drum and control shaft.
In particular, the apparatus of the present invention includes: a drum body, defining an axial passage adapted to receive the control shaft of an adjustable covering for an architectural opening; at least a first adjustable friction element (such as a spring leg) mounted on the drum body, the first adjustable friction element being moveable from a resting position to a release position; wherein the first adjustable friction element into the axial passage when in the resting position and does not encroach into the axial passage when in the release position.
The control system of the present invention includes a control shaft having an axis of rotation and having an axial length substantially in excess of its diameter; a drum body, slidably mounted on the control shaft and rotatable about the axis of rotation of the control shaft, the drum body including first and second ends and an axial hole being adapted to a receive the control shaft; at least a first adjustable friction element (such as a spring leg) mounted on the drum body, the first adjustable friction element being moveable from an engaged position to a release position; wherein the first adjustable friction element, when in the engaged position, impedes the drum body from sliding relative to the control shaft, and, when in the release position, permits the drum body to slide relative to the control shaft.
The apparatus and system of the present invention can be advantageously used to secure a control shaft in an adjustable covering for an architectural opening. The method of the present invention includes the following steps: inserting a control shaft into one end of an axial hole defined by a drum body; releasing an adjustable friction element (such as a spring leg) mounted on the drum body to permit the control shaft to slide completely through the drum body via the axial hole; sliding the drum body to a desired position on the control shaft; engaging the adjustable friction element to impede further sliding of the drum body relative to the control shaft; fixedly attaching a drum support to a headrail housing; and substantially impeding movement of the drum body relative to the headrail housing except for rotation of the drum body about the axis of rotation of the control shaft.
The present invention is described in greater detail with respect to the following drawings.
REFERENCES:
patent: 2469839 (1949-05-01), Nelson
patent: 2589846 (1952-03-01), Nelson
patent: 2667220 (1954-01-01), Rutledge
patent: 2670038 (1954-02-01), Lorentzen
patent: 4623012 (1986-11-01), Rude et al.
patent: 5228491 (1993-07-01), Rude et al.
patent: 5341865 (1994-08-01), Fraser et al.
patent: 5495153 (1996-02-01), Domel et al.
patent: 5662154 (1997-09-01), Drake, III
patent: 76262/91 (1991-11-01), None
patent: 2162443 (1996-05-01), None
patent: 82239134 (1983-01-01), None
patent: 29508479 (1995-09-01), None
patent: 2076454 (1983-09-01), None
patent: 161962 (1972-02-01), None
Dorsey & Whitney LLP
Hunter Douglas Inc.
Purol David M.
LandOfFree
Control drum with adjustable friction does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control drum with adjustable friction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control drum with adjustable friction will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2601620