The present invention relates to master carriers that pull traversing motorized drapery systems, specifically to the ability to disconnect a master carrier drive mechanism from the carrier train that supports the drapery or curtain fabrics or materials.
Drapery support systems that permit opening and closing of the draperies are well known. Such systems commonly consist of an aluminum, steel or plastic headrail that contains a series of roller or sliding carriers. These carriers have drapery fabric or material connected to them by some form of a drapery hook or other means. Depending on the form of pleating, these carriers are spaced at approximately three inches. Also depending on the pleating system the individual carriers may or may not be not directly connected to each other. In the most common form they are indirectly connected by means of the suspended drapery fabric. A lead carrier or master carrier is normally connected to the foremost end of the drapery fabric.
The master carrier is most commonly attached to a drive cord that is guided inside the metal or aluminum headrail, between the side walls of the headrail. At each end of the headrail, the drive cord is normally guided through a free-wheel pulley at the non-drive end and through a drive pulley at the drive end. In its most common manually operable form, the drive cord is guided down vertically at the drive end where it loops down. By pulling one end of the looped down cord the drapery will be closed, by pulling the other end the drapery will be opened. Some drapery systems do not have a drive cord, but are operated by pulling a wand that is connected to the drive carrier. Instead of being actuated by a cord, some systems are driven by a steel wire or a belt.
Drapery systems may consist of one panel which opens towards one end only (one-way opening), or they may consist of two panels which then close towards the center and open by pulling the panels each to one end (center opening). In the case of very long windows, more than two panels may be hung from the same headrail, for simultaneous opening with a single drive motor.
To avoid excessive wear and tear of drapery fabrics, it is generally not recommended to open and close drapery panels by pulling on the drapery fabrics or materials themselves. Especially on cord actuated systems, the required force to pull a drapery open or close by means of pulling the fabric instead of the cord may require considerable force and result in damage to the fabric or the system.
Motor powered drapery systems are known in either a direct drive version or an indirect drive version. In a direct drive version, the motor is directly connected to the headrail and the rotation power is transmitted to the drive cord or belt via a gear mechanism. An indirect drive version includes cord-drive motors that are normally mounted at some distance below the drapery headrail and have a vertical loop of the drive cord that extends below the headrail, guided through a pulley attached to the motor. Cord drive motors are usually hard to conceal, tend to require more maintenance for cord adjustments, and are usually less powerful than direct drive motors. Cord drive motors are more commonly used to retrofit manual cord driven drapery systems.
Direct drive drapery motors are normally outfitted with a pulley or sprocket that provides traction to rotate the drive cord, belt or wire. The master carrier of the drapery system is normally attached to the drive belt, cord or wire by means of a fixed connection.
Because direct drive motors are normally fully concealed behind the drapery fabric it is often not apparent to a user that a drapery system is motorized. An unsuspecting user may be tempted to start pulling on the fabric to open or close a drape which will require rotation of the motor. However, since such rotation is prevented by the direct drive connection, this could create damage to the mechanism or fabric if excessive force were applied by the user.
To prevent such damage from occurring by inadvertent manual operation by a user, it is necessary to have a method or mechanism to permit easy manual movement of the drapery fabric without damage to the electric drive system, such as by means of a disconnect between motor and drive cord, belt or wire when there is no current applied to the motor. There are currently two methods to achieve this: the electro magnetic shaft disconnect and the overlap master disconnect.
The electromagnetic shaft disconnect consists of a motor shaft that connects the drive shaft of the direct drive motor with a cord drive pulley. By applying power to the motor, magnets in the electromagnetic disconnect get actuated and pull the shaft end into a matching opening of the drive pulley, thus establishing a fixed connection between motor and drive wire. The disadvantage of this system is that it is most commonly operated by drive motors that are started and stopped by means of current sensing. They require considerable torque surges and as a consequence tend to be noisy.
Prior art disconnecting devices exist most commonly in two versions. The first version consists of a spring loaded nipple attached to the traveling master carrier which matches with a depression in a connector block mounted against the inside of a perforated drive belt. Because of space considerations, the microdimensions make the system extremely sensitive to wear and permit only very light drapery weight loads.
The other commonly known version consists of a master carrier featuring a single levered arm provided with one single multipurpose spring. By pulling the far end of the drapery downward, the levered arm frees the locking pin from the portion of the master carrier that is connected to the drive belt. This way the drapery fabric can be moved by hand.
The disadvantage of this system is that there is only one spring to handle both the drapery load function and the locking spring function. This requires that the spring action be strong enough to carry the drapery load, keep it in position and pull the arm back into position, but not so strong that it would prevent the locking pin from sliding back into its connector. The use of a single spring for this dual purpose severely limits the maximum allowable load on the arm. Currently this is commonly limited to a maximum of 0.5 kg vertical load.
The load limitation imposed by the single arm and single spring concept of the prior art places severe limitations on the motorized drapery system. In many instances motorized systems are used to eliminate the need for manual operation of large and heavy drapery systems. Weight limitations impose severe restrictions on the range of applications. Furthermore the maximum allowable weight due to the spring capacity can easily be exceeded, which would cause the load to lower the levered arm and free the connection between master carrier and drive belt. This would result in a malfunction of the motorized system when power is applied.
It is therefore an object of the invention to overcome at least some of the foregoing disadvantages of prior art systems.
It is a further object of the present invention to separate the vertical load capacity from the locking mechanism, so that the load capacity can be increased without diminishing the locking ability.
In accordance with one embodiment of the present invention, a disengageable master carrier assembly for a motor driven drapery is provided having a master carrier block section and a locking block section. The locking block section has entrance ramps and a detent or pocket that is sized to receive an engagement member mounted to the master carrier block section. The master carrier block assembly has:
a support arm for supporting a leading edge of drapery fabric, the support arm being supported by a first resilient member, the amount of resilient support for the support arm provided by the resilient member being changeable to adapt to drapery fabrics of different weights, such that the support arm will support the leading edge of drapery fabric and be held in an engaged operating position by the resilient support member when no manual force is applied to the leading edge of the fabric and will be displaced to a disengaged position when a manual force is applied to the leading edge of the fabric; and
an engagement member sized for fitting into the detent pocket of the locking block member, the engagement member being resiliently urged by a second resilient member disposed between a movable portion of the support arm and a part of said engagement member.
The second resilient member has a resilience such that:
the engagement member will be urged into its engaged position in the detent pocket of the locking block section when the engagement member is aligned with the detent pocket and when the support arm is in its engaged position,
displacement of the support arm to its disengaged position will cause the second resilient member to be sufficiently displaced to move the engagement member out of the detent pocket of the locking block section, to permit disengagement of locking block section from the master carrier block section, and
direct force applied to the engagement member by the entrance ramps of the locking block section as the engagement member rides on the ramps during a re-engagement process will move the engagement member toward a disengaged position, against the urging force applied by the second resilient member, with the support arm in its engaged position.
The foregoing and other objects, features and advantages will be apparent to those skilled in the art upon review of the detailed description herein, with reference to the drawings, in which:
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Longer arm 115 is pivoted about pivot 130 and held against the weight of the drapery fabric by a firm load-carrying spring 120 disposed in a cylinder 121 in the master carrier block, pressing upwardly on the rear end 135 of longer arm 115, behind the pivot 130 for the longer arm 115. Longer arm 115 could also be held in place by positioning spring 120 forward of the pivot 130, so it pressed upwardly on the bottom of the front 132 of longer arm 115. In the embodiment depicted, the longer arm 115 can be approximately parallel to the headrail 102, the position being determined by stops 117 on the master carrier block body 116, though a parallel position of the longer arm 115 is not mandatory.
The resilience of spring 120 can be adjustable by means of a set screw 139 for various vertical load carrying capacities. In this way, the disengaging force required can be adjusted depending on the weight of the drapery fabric selected. Furthermore different strength springs may be used to increase or decrease load capacity further if necessary for different draperies or headrail designed.
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The pre-set end stops of the electric drive system are not affected by the manual operation because the position is determined by the rotation of the drive belt. This ensures ongoing accurate opening and stacking position of the draperies and maintaining of the final preset desired drapery end position. These end position may be preset and controlled by Silent Stop™ (a trademark for a BTX, Inc. product for controlling the drapery stopping position of an electric motor driven drapery) or by other means.
Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that the claims will cover any such modifications or embodiments that fall within the true scope and spirit of the invention.
This application relates to, and claims the benefit of the filing date of, co-pending U.S. provisional patent application Ser. No. 60/864,702 entitled “DRAPERY MASTER CARRIER WITH AUTOMATIC DISENGAGER,” filed Nov. 7, 2006, the entire contents of which are incorporated herein by reference for all purposes.
Number | Date | Country | |
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60864702 | Nov 2006 | US |