Referring now to
The segments 1 and 2 may be circular in cross section or may have a cross section that is rectangular or of other geometry as will be known to those skilled in the art. Although not necessary, it is preferable that the segments 1 and 2 have cross sections which are geometrically similar.
Each of the segments 1 and 2 has a hollow axial bore or opening. Segment 1 has a larger cross section than each of segments 2. The opening in segment 1 has a diameter slightly larger than a corresponding outer diameter in segment 2 whereby each of the segments 2 may be slidably received or nested within segment 1. A minimum overlap P between a short segment 2 and a long segment 1 within which the short segment 2 is nested must be maintained to prevent instability and separation of the rod formed by the segments 1 and 2.
In accordance with the invention, the long segment 1 has a length equal to L and each of the short segments 2 has a length equal to S where L=S+2P.
As can be seen in
Referring now to
P will vary with the rigidity of the materials from which the members are formed, the tightness of the fit, and the geometry of the rod segments. P should preferably be in the range of 0.04S-0.08S. Goods results have been found when P=0.06S in that sagging and separation of overlapping segments is prevented while the maximum length of to which the curtain rod may be extended is no unduly shortened.
In the disposition shown in
Referring now to
The central one of the three short segments 2 shown in
Referring now to
Thus it is seen that a single telescoping curtain rod formed from three segments of only two sizes can be used alone or in combination with anther such rod to span distances from twice the length of the smaller segment to five times the length of the smaller segment, as shown below.
L=length of long segment 1
S=length of each short segment 2
P=length of each overlap
R1min=minimum length of rod formed from two short segments 2 and one long segment 1.
R1max=maximum length of rod formed from two short segments 2 and one long segment 1.
R2min=minimum length of rod formed from three short segments 2 and two long segments 1.
R2max=maximum length of rod formed from three short segments 2 and two long segments 1.
S=L−2P or L=S+2P
R1min=2S
R1max=L+2S−2P
R2min=3S=L+2S−2P
R2
max=2L+3S−4P=5S
R2max/R1min=5S/2S=5/2
That is, the minimum length achievable using the two short segments 2 and one long segment 1 of one rod is equal to twice the length of the short segment 1. The maximum length achievable by combining two long segments and three short segments taken from two rods is five times the length of a short segment 1.
From the segments of two rods, each consisting of one long segment 1 and two short segments 2, a curtain rod can be formed having any length within a continuous range extending from R1min to R2max.
It is to be appreciated that variations and modifications may be made to the invention without departing from the spirit and scope of the invention. For example, the cross sectional dimensions of the long segments 1 and short segments 2 may be interchanged whereby the long segments are nested or slidable within the short segments. Also, although the rods have been described as those used for hanging curtains, the invention will have utility with rods used in other applications, e.g., closet rods for hanging clothing, chinning rods for exercise, pipes used for plumbing, conduit for electrical lines, etc.
Number | Date | Country | |
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60823815 | Aug 2006 | US |