This invention relates generally to roller blinds, or roller shades, and in particular to a new and novel locking tensioner for a cord or chain of a roller blind or roller shade.
One common form of window shade or window covering comprises a fabric or other material that is wound upon a roller that is fixed or mounted to the top portion of the window frame. The fabric can be pulled downwardly and unrolled from the roller in order to block or minimize the amount of light infusion through the window. When it is desired to allow unrestricted light to pass through the window the fabric is typically wound back onto the roller through the use of one of a wide variety of different mechanical mechanisms. Most commonly, a looped rope, cord to chain is operatively connected to the roller through the use of a clutch. Pulling on one of the legs of the rope, cord or chain will typically cause the clutch to impart rotational movement to the roller in a first direction, which will either unwind the fabric from the roller or rewind the fabric back onto the roller. Similarly, pulling downwardly on the other leg of the rope, cord or chain will cause the roller to rotate in the opposite direction. Since the roller and the clutch mechanism will be mounted at the top of the blind, and at the top of window frame, in many cases a relatively long cord or chain is required, particularly for windows or openings of a substantial vertical height. Unfortunately, long looped ropes, cords or chains have been found to present strangulation hazards for small children, and sometimes pets.
As a result of the potential for children and/or pets to become entangled about long loops of chain or cord hanging from a roller blind, a number of jurisdictions have legislated regulations stipulating that, when properly installed, the roller blind must not operate unless a cord tensioner is in place. Such cord tensioners must be fastened to a wall or window frame in order to hold the cord or chain tightly against the side of the wall or window frame and to eliminate or substantially reduce the likelihood of a child becoming entangled in the cord or chain. From a blind operational perspective the tensioner must hold the two legs of the looped cord relatively parallel in order to ensure a smooth operation of the clutch mechanism. In some jurisdictions, regulations further stipulate that the tensioner must effectively render the roller blind inoperable should the tensioner not be secured to a wall or frame, or should it at some point become detached from the wall or window frame.
Accordingly, the present invention concerns a mechanism that assists in maintaining a rope, cord or chain of a roller in tension and secured to a wall or window frame when the blind is operational. The invention also assists in rendering the roller blind inoperable, or partially inoperable, should the mechanism become detached or partially detached from the wall or window frame.
There is therefore provided a locking tensioner for a roller blind, the roller blind of the type having a roller and a looped chain or cord to impart rotational movement to the roller, the locking tensioner comprising first and second members, each of said first and second members having a first end and a second end, said first ends having apertures dimensioned to receive therethrough the chain or cord of the roller blind, said first and second members rotatably secured to one another and rotatable about an axis between a locked and an unlocked configuration, when in said unlocked configuration said apertures aligned permitting the chain or cord to freely move through both of said apertures, when in said locked configuration said apertures at least partially misaligned restricting the movement of the chain or cord through said apertures, said locking tensioner including a spring biasing said first and second members toward said locked configuration.
There is also provided a locking tensioner for a roller blind, the roller blind of the type having a roller and a looped chain or cord to impart rotational movement to the roller, the locking tensioner comprising first and second members, each of said first and second members having a first end and a second end, said first ends having apertures dimensioned to receive therethrough the chain or cord of the roller blind, said first and second members rotatably secured to one another and rotatable about an axis between a locked and an unlocked configuration, when in said unlocked configuration said apertures aligned permitting the chain or cord to freely move through both of said apertures, when in said locked configuration said apertures at least partially misaligned restricting the movement of the chain or cord through said apertures, each of said second ends containing an opening for the passage of a fastener, said second ends aligned and overlying one another when said locking tensioner is in said unlocked configuration to permit a fastener to be received through both of said second ends to secure said tensioner to a window frame, said locking tensioner including a spring biasing said first and second members toward said locked configuration.
Further aspects of the invention will become apparent from the following description taken together with the accompanying drawings.
For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings which show exemplary embodiments of the present invention in which:
The present invention may be embodied in a number of different forms. The specification and drawings that follow describe and disclose some of the specific forms of the invention.
Referring to the attached drawings, there is shown a generic roller blind 1 of the type having a roller 2 and a looped chain or cord 3 to impart rotational movement to the roller. Typically, the chain or cord will be in a continuous loop and received about a clutch or drive mechanism 4 that imparts rotational movement to the roller in either a clockwise or counter-clockwise direction, depending on which leg of the chain or cord is pulled in a downward fashion. In that matter, blind fabric 5 can either be lowered in front of window 6 or retracted back on to roller 2.
For purposes of safety, and in many cases to comply with local jurisdictional regulations, the roller blind will include a locking tensioner 7. One of the primary purposes of tensioner 7 is to hold the chain or cord 3 taughtly and securely to the frame of window 6, or in some cases to an adjacent wall or other fixed or rigid structure.
With specific reference to
First and second members 8 and 9 are rotatably secured to one another and rotatable about an axis 15 between a locked (see
In the embodiment of the invention shown in
In a preferred embodiment of the invention spring 16 is a torsion spring that includes a helical portion 17 and a pair of arms 18. Each of arms 18 bears against a different one of first and second members 8 and 9. Helical portion 17 comprises axis 15 about which the first and second members rotate when moving between their locked and unlocked configurations. First ends 10 have smooth inner faces 19 that are in “scissor-like” or “by-pass” contact with each other and slidable past one another when the locking tensioner moves between its locked and unlocked configurations. When the locking tensioner is in its locked configuration torsion spring 16 will bias first ends of 10 in opposite rotational directions, thereby applying a shear load upon a chain or cord that is received through apertures 12. The shear loading of the chain or cord restricts its movement through the apertures and limits or prevents rotation of roller 2.
The functionality and operation of locking tensioner 7 will now be described in further detail with specific reference to the drawings. In the case of the embodiment shown in
Should for any reason the fastener become detached or partially detached from the window frame the force counter acting the action of torsion spring 16 will be either minimized or removed, causing the arms of the spring to rotate the first and second members about the spring's helical portion. Locking tensioner 7 will thus be rotated from its unlocked to its locked configuration with the inner faces 19 of the first and second members moving in “scissor-like” or “by-pass” contact until each of the faces comes into contact with the chain or cord, applying a shear load to the chain or cord. The strength of torsion spring 16 and the first and second members is such that the chain or cord will not be sheared off, but rather the chain or cord will be held or gripped by the first and second members. Such a configuration is shown in
The embodiment shown in
It is to be understood that what has been described are the preferred embodiments of the invention. The scope of the claims should not be limited by the preferred embodiments set forth above, but should be given the broadest interpretation consistent with the description as a whole.
Number | Date | Country | Kind |
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2850673 | Apr 2014 | CA | national |