Patent Application
20200123853
The present invention relates generally to a position-fixing system, and more particularly to a position-fixing system for the covering material of a window covering.
A conventional cordless roller shade includes a rotatable roller tube horizontally provided under a support. By rotating the roller tube, the covering material of the roller shade can be rolled up or released. A weight rod is provided below the covering material to be easily grasped and to add weights. The covering material can be expanded by simply pulling down the weight rod. Furthermore, once the downward pulling force is dismissed at any position during the lifting or lowering, a braking mechanism of the roller shade will be immediately activated, which overcomes the rewinding force generated by a spring mechanism hidden inside the roller tube, so that the covering material can remain in an unmoving limited state. If the user wants to roll up the covering material, he or she has to pull the weight rod downward first to dispel the limited state secured by the braking mechanism, and then let go the weight rod, letting the rewinding force of the spring mechanism take over, whereby drives the roller tube to automatically roll up the covering material.
To ensure sufficient rewinding force, it is common for conventional roller shades to use prestressed springs with high elasticity. However, applying such prestressed springs indirectly increases the manufacturing cost. In addition, while rolling up a conventional roller shade, the user usually has to pull down the weight rod first, or the limited state secured by the braking mechanism cannot be dispelled. This kind of operation is inconvenient for roller shades mounted inside window frames, for the weight rod of such a roller shade would be very close to the bottom margin of the window frame when the covering material is fully expanded.
In view of the above, one aspect of the present invention is to provide a position-fixing system which could be applied to various kinds of window coverings. The position-fixing system provided in the present invention could be easily operated and would be able to fix the position of the covering material promptly with high reliability.
The present invention provides a position-fixing system for a window covering, wherein the window covering has a covering material, a roller tube, and a support. The roller tube is pivotably connected to the support. The covering material has an end connected to the roller tube, and is adapted to be expanded from or wound around the roller tube. The position-fixing system includes a variable diameter screw, a guiding portion, and an elastic member. The variable diameter screw is fixedly connected to the support, wherein the variable diameter screw is defined to have an axis, and is defined to have a first end and a second end in an extension direction of the axis. The variable diameter screw has a working section, which gradually and radially broadens in a direction from the first end toward the second end. The guiding portion is connected to an inner wall of the roller tube, wherein the guiding portion extends in an axial direction of the roller tube. The elastic member fits around the variable diameter screw, wherein the elastic member is adapted to slide along the guiding portion. The elastic member has a meshing portion provided along an inner side thereof and a guided portion provided along an outer side thereof. At least a part of the meshing portion meshes with the working section of the variable diameter screw. The guided portion contacts the guiding portion, and is adapted to slide along the guiding portion. When the roller tube rotates in a first rotation direction, the elastic member moves along the working section of the variable diameter screw in a direction from the first end toward the second end, and the elastic member deforms correspondingly; as the elastic member deforms, the elastic member exerts a gradually increasing unit tightening force to the variable diameter screw in a radial direction of the variable diameter screw, whereby to dampen a rotation of the roller tube in the first rotation direction.
With the aforementioned design, when the roller tube rotates in a first rotation direction, the elastic member moves from the first end toward the second end along the working section of the variable diameter screw, and therefore deforms, whereby to increasingly exert a unit tightening force to the variable diameter screw in a radial direction thereof. In this way, the rotation of the roller tube in the first rotation direction would be hindered. In consideration of the change in the effective weight applied to the roller tube while the covering material is being rolled up or expanded, the working section which gradually broadens in the radial direction of the variable diameter screw is applied in the present invention, so that the unit tightening force exerted to the variable diameter screw could be changed during the rotation of the roller tube, and the change of the unit tightening force would correspond to the degree of expansion of the covering material, whereby to precisely fix the position thereof.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
The present invention will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which
The position-fixing system 20 of the current embodiment includes a variable diameter screw 21, a guiding portion 22, and an elastic member 23, as shown in
In the current embodiment, the elastic member 23 is anon-closed elastic ring of a certain thickness, and is roughly round, as shown in
When the roller tube 12 rotated in a first rotation direction R1, the elastic member 23 slides along the guiding portion 22 with the outer side thereof, and crawls along the working section 212 of the variable diameter screw 21 with the inner side thereof, whereby the elastic member 23 moves in the moving direction D1. The change of the elastic member 23 relative to the working section 212 of the variable diameter screw 21 is shown in
In the current embodiment, the axial direction 121 of the roller tube 12 is collinear or in parallel with the axis 211 of the variable diameter screw 21.
As shown in
In addition, there can be more than one guiding portion 22 provided on the inner wall of the roller tube 12. In the current embodiment, there are two guiding portions 22 correspondingly provided on the upside and the downside of the inner wall of the roller tube 12. However, the number of the guiding portion 22 does not affect the provided effect.
The variable diameter screw 21 includes a screw body, wherein the screw body has threads provided on an outer surface thereof, as shown in
As mentioned above, in the current embodiment, the elastic member 23 is a non-closed elastic ring of a certain thickness. Herein we define a side of the elastic member 23 facing the variable diameter screw 21 is an inner side, and another side thereof facing the roller tube 12 is an outer side. The meshing portion 231 is provided on the inner side of the non-closed elastic ring, and the guided portion 232 is provided on the outer side of the non-closed elastic ring. Furthermore, the meshing portion 231 has threads appropriately matching the threads of the variable diameter screw 21, so that the meshing portion 231 of the non-closed elastic ring can mesh with the working section 212 of the variable diameter screw 21.
It is worth mentioning that, the working section 212 defined in the present invention refers to a segment on the variable diameter screw 21 which provides a mechanical advantage in the moving of the elastic member 23. In the current embodiment, it is represented by the points of application of force on the variable diameter screw 21 which drive the elastic member 23 to crawl. The working section 212 can be constituted by crests, troughs, and walls of the threads, and alternatively, can be constituted merely by at least part of the crests of the threads, merely by at least part of the troughs of the threads, or merely be at least a part of the walls of the threads. Whether the working section 212 of the variable diameter screw 21 is constituted by the crests or troughs or walls of the threads depends on the structures of the corresponding elastic member 23 itself and the meshing portion 231 thereof.
It is worth mentioning that, in the present invention, the meshing between at least a part of the meshing portion 231 and at least apart of the working section 212 of the variable diameter screw 21 is defined as an effective meshing segment EF. As mentioned above, the effective meshing segment EF in the current embodiment is the meshing between the whole meshing portion 231 on the inner side of the elastic member 23 and the corresponding part of the working section 212 of the variable diameter screw 21.
The position-fixing system 20 further includes an ample space 24, which is provided inside the roller tube 12, and is adjacent to the elastic member 23. The ample space 24 allows the elastic member 23 to deform. In the current embodiment, the elastic member 23 has two ends 233 provided in a circumferential direction thereof, whereby to form a non-closed elastic ring. The ample space 24 is located at the two ends of the non-closed elastic ring. With such design, when the elastic member 23 moves along the variable diameter screw 21 in the moving direction D1, the main body of the elastic member 23 deforms toward the two ends 233, and the ample space 24 reduces in the radial direction of the working section 212.
The elastic member 23 can be integrally made of silicone or rubber. To further concentrate the stress created by the deformation of the elastic member 23 onto the working section 212 of the variable diameter screw 21, and to prevent the guiding portion 22 from interfering with the sliding of the guided portion 232 of the elastic member 23 in the axial direction 121 of the roller tube 12, the position-fixing system 20 further includes at least a non-closed rigid ring 25, which fits in at least one circumferential groove 234 of the elastic member 23 to provide an inward holding force to the elastic member 23 which deforms as a whole. It is worth mentioning that, even if the elastic member 23 is integrally made of silicon or rubber materials, its thickness and Young's modulus could be also adjusted to provide the effect of preventing the guiding portion 22 from interfering with the sliding of the guided portion 232 of the elastic member 23 in the axial direction 121 of the roller tube 12.
In addition, the non-closed rigid ring 25 also passes through the guided portion 232 of the elastic member 23, i.e., where the groove is. Similarly, the non-closed rigid ring 25 does not affect the technical effect that the guiding portion 22 does not interfere with the sliding of the guided portion 232 of the elastic member 23 in the axial direction 121 of the roller tube 12, but mutually interfere with the guided portion 232 in the first rotation direction R1 of the roller tube 12.
As shown in
The arrangement of a position-fixing system 30 of a second embodiment of the present invention in the roller shade 10 is shown in
The position-fixing system 30 of the current embodiment includes a variable diameter screw 31, a guiding portion 32, and an elastic member 33, as shown in
As shown in
As shown in
As shown in
In addition, there can be more than one curved groove 333 provided on the inner side of the elastic member 33. In the current embodiment, there are two curved grooves 333 symmetrically provided on the inner side of the elastic member 33, wherein one is on the upside and the other is on the downside. However, the number of the curved grooves 333 does not affect the provided technical effect.
Besides, when it comes to the arrangement of the aforesaid teeth 3311, 3312 on the inner side of the elastic member 33 in the circumferential direction, the deformation of the elastic member 33 can be guided to directions other than the radial direction r by not providing them in the same radial direction r with the curved grooves 333.
It is worth mentioning that, whether the elastic member 33 has the curved groove 333 provided or not, and no matter how the curved groove 333 and the teeth 3311, 3312 are staggered in the circumferential direction of the elastic member 33, it is possible for the elastic member 33 to provide its required function merely by the material of itself.
The elastic member 33 can be integrally made of silicone or rubber. The position-fixing system 30 further includes an ample space 34, which is inside the roller tube 12 and is adjacent to the elastic member 33. In the current embodiment, the ample space 34 is located between the slightly elliptical elastic member 33 and the roller tube 12. Therefore, when the elastic member 33 is moved along the variable diameter screw 31 in the moving direction D1, the main body of the elastic member 33 deforms in a direction toward the inner wall of the roller tube 12, and the ample space 34 reduces as the working section 312 increases in the radial direction thereof.
Therefore, the elastic member 33 radially exerts a gradually increasing unit tightening force Fb to the working section 312 of the variable diameter screw 31 in the moving direction D1, as shown in
The arrangement of the roller shade 10 applied with a position-fixing system 40 of the third embodiment of the present invention is shown in
In the current embodiment, the position-fixing system 40 includes a variable diameter screw 41, at least one guiding portion 42, and an elastic member 43, as shown in
As shown in
A distance between the two ends 432a, 432b of the tightening spring is at least greater than a width between the parallel ribs 421 of each of the guiding portions 42. Both the ends 432a, 432b of the tightening spring abut against one side of the corresponding guiding portion 42, whereby the tightening spring is adapted to slide along the corresponding guiding portion 42.
Please refer to
In the current embodiment, when the elastic member 43 is moved in the moving direction D1, the end 432a of the tightening spring always abuts against one side of one of the ribs 421 of the corresponding guiding portion 42, and the tightening spring slides along said rib 421. On the other hand, the other end 432b of the tightening spring can be moved freely in the circumferential direction of the variable diameter screw 41, for the working section 412 of the variable diameter screw 41 gradually broadens in the radial direction thereof.
Therefore, the elastic member 43 exerts a gradually increasing unit tightening force Fc to the working section 412 of the variable diameter screw 41 in the radial direction thereof, as shown in
Please refer to
With the aforementioned design, the insert groove 442 matches the guiding portion 42 of the roller tube 12 (i.e., the parallel ribs 421), and therefore the disc body 441 is adapted to slide in the roller tube 12 along the ribs 421. The holding portion 443 of the support disc 44 holds the rim 413 of the variable diameter screw 41 in a snap-fitting way, so that the support disc 44 can be coaxially rotated with the roller tube 12 without driving the variable diameter screw 41 to rotate.
The support disc 44 supports the variable diameter screw 41 in the roller tube 12, which prevents the variable diameter screw 41 from being bent by its own weight. However, in embodiments not provided with a support disc, such problem can be still overcome merely through the adjustment in the material of the variable diameter screw 41.
With the above design, when the roller tube 12 rotates in a first rotation direction R1, the elastic member will be moved along the working section of the variable diameter screw 41 from the first end P1 toward the second end P2, causing deformation. Whereby, a gradually increasing unit tightening force will be exerted to the variable diameter screw in the radial direction, dampening the rotation of the roller tube 12 in the first rotation direction R1. On the other hand, when the roller tube 12 is rotated in a second rotation direction opposite to the first rotation direction R1, the unit tightening force exerted by the elastic member to the variable diameter screw in the radial direction will gradually decrease.
With the aforementioned arrangements, when the covering material 11 is being lifted or expanded, the elastic member and the roller tube 12 rotate synchronously, wherein the elastic member moves in an axial extension direction of the variable diameter screw, generating a variable friction between the elastic member and the variable diameter screw. In this way, when the operation stops, the position of the covering material 11 of the window covering could be precisely fixed. Furthermore, in consideration of the change in the effective weight applied to the roller tube 12 while the covering material 11 is being lifted or expanded, the present invention uses a variable diameter screw which has a working section broadening in the radial direction, so that the unit tightening force exerted to the variable diameter screw could be changed in a way that corresponds to the degree of expansion of the covering material 11 during the rotation of the roller tube 12, whereby to precisely fix the position of the covering material 11.
Further, the rotation of the roller tube 12 is caused by the equilibrium between the weight corresponding to the lifting or lowering of the covering material 11, the restoring force provided by the power mechanism 14, and the manual operating force. The stillness of the roller tube 12 corresponds to the equilibrium between the aforesaid weight, restoring force, and friction. With the position-fixing system of the present invention, the covering material 11 could be precisely stopped at where it is when the operation stops, without being shifted upward or downward. In addition, the position-fixing system of the present invention can be applied in all kinds of window coverings with roller tubes; it could be operated easily, and could provide the effects of immediate and reliable position-fixing.
It must be pointed out that the embodiments described above are only some preferred embodiments of the present invention. All equivalent structures which employ the concepts disclosed in this specification and the appended claims should fall within the scope of the present invention.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
