Tension rod mechanism with opposing threads
View Patent ↗A tension rod mechanism for a tension rod having a first outer shaft with a second inner shaft slideable therein. A first collar receiveable in the first outer shaft of a tension rod for rotational movement therewith and slidable axial movement relative thereto threadingly engages a tapered first threaded shaft and is configured to apply a outwardly-directed radial force to the first outer shaft. A second collar fixedly receivable in the second inner shaft for movement therewith engages the second threaded shaft. A first rotation of the first outer shaft relative to the second inner shaft increases the outwardly-directed radial force applied by the first collar to the first outer shaft, and a second rotation in an opposite direction increases the axial distance between the first and second collars.
1. A tension rod comprising:
a first outer shaft;
a second inner shaft slideably received by the first outer shaft and rotatable about a longitudinal axis of the tension rod; and
a tension rod mechanism operatively coupling the first outer shaft and the second inner shaft, the tension rod mechanism comprising:
a tapered first threaded shaft having a first end and an opposing second end, and being completely threaded with a first screw thread having a first thread direction from the first end to the second end, and completely tapered from the first end to the second end, a diameter of the first end of the tapered first threaded shaft being larger than a diameter of the second end of the tapered first threaded shaft;
a first expandable collar threadingly engaged with the first threaded shaft, the first collar configured to be received in the first outer shaft for rotational movement therewith and slidable axial movement relative thereto and to apply an outwardly-directed radial force to the first outer shaft;
a second threaded shaft having a second screw thread with a second thread direction opposite the first thread direction, the second threaded shaft being fixedly connected to the first threaded shaft; and
a second collar threadingly receiving the second threaded shaft therein and being fixedly received in the second inner shaft for movement therewith, the second collar having a longitudinally extending second collar stopper projecting in the direction of the central flange stopper;
a center flange integrally formed as a single part with and located between the first threaded shaft and the second threaded shaft, the center flange having a radially projecting central flange stopper;
wherein relative rotation between the first outer shaft and the second inner shaft in a first direction draws the second collar stopper into circumferential abutment with the central flange stopper and prevents relative rotation between the second collar and the second threaded shaft, further rotation between the first out shaft and the second inner shaft after abutment of the stoppers causes the tapered first threaded shaft to apply the outwardly directed radial force to fixedly couple the first collar to the first outer shaft, after the first collar is fixedly coupled to the first outer shaft relative rotation between the first outer shaft and the second inner shaft in an opposite second direction increases the distance between the first and second collars.
2. The tension rod mechanism according to claim 1 , wherein the first collar has a longitudinally extending circumferentially expandable slot.
3. The tension rod mechanism according to claim 1 , wherein the second threaded shaft has a constant diameter along the longitudinal axis.