KR960015120B1 - Monocontrol venetian blind - Google Patents

Abstract

Headrail hardware to lift and tilt a Venetian blind is provided. A single control (5) operates both the lift and the tilt function. A multiturn band brake tilter (19) is used with each ladder cord (15) in a way that reduces the frictional forces encountered in lifting or lowering the blind. One end of each of the ladder cords is attached to an arm (21) of its tilter. The tilters are disposed directly about the rotating drive rod (11) with no intermediate parts, and are supported by cradles (17) that mount in the headrail rather than by the drive rod (11) as in prior art blinds. The drive rod (11) rotates the tilters (19) and the lifting mechanism until the tilters (19) contact stops built into each of the cradles (17). Further rotation keeps the blind fully tilted while lifting or lowering of the blind continues. In the preferred embodiment, the lift cords (13) are attached to the drive rod (11), which traverses to accumulate the cords (13) in a single layer as the rod (11) is rotated to lift the blind. The rotation of the rod (11) within the tilters (19) greatly reduces the lateral force needed to traverse the rod (11). An innovative bearing support (41) is provided so that the weight of the blind is transferred from the tilter (19) directly to the cradle (17), further reducing the frictional drag on the traversing rod (11).

Description

[Name of invention]

Single Adjustment Venetian Blinds

[Brief Description of Drawings]

Other objects, features and advantages of the present invention will become apparent upon review of the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1 is a vector line diagram of the force F ₁ required to cause lateral movement without other motion, where F ₁ is equal to μW in this state.

FIG. 2 is a vector diagram of the forces F ₁ , F ₂ and their combined μW, where much less F ₁ than μW is the force required to cause lateral movement when there is another motion at the same interface.

3 is an isometric view of the venetian blind head rail cut away to show some embedded parts.

4 is an enlarged view of a portion of the mechanism of FIG. 3 to better show details of the lifting and tilting components and features of the preferred embodiments of the present invention.

5 is an enlarged side view showing, in cross section, a portion showing a tilt mechanism, a transverse rod and a cradle according to a conventional raised ramp mechanism at one of the lift points.

6 shows elements of a tilt mechanism supported by a cradle in accordance with the principles of the present invention.

FIG. 7 is the same as FIG. 5 but shows the tilt mechanism being rotated 90 degrees while raising the blinds.

FIG. 8 is an enlarged side view, partly in cross section, showing another embodiment of the present invention employing a cord for blind raising or a bush for tape; FIG.

Detailed description of the invention

Background of the Invention and Prior Art

The present invention relates to venitian blinds, and more specifically to mono control venetian blinds using the same actuating device in controlling the inclination of the slats and raising and lowering the blinds.

The headrail structure of the venetian blinds must provide two actions: firstly raising and lowering the blinds and secondly opening and closing the blinds by tilting the slats adjustablely, To fix it at an angle. An ideal single-adjustment headrail mechanism requires less operating effort, even when lifting heavy and long blinds. An ideal headrail mechanism will accumulate a lift cord or tape in the headrail in a relatively small space and have a filt mechanism that can be closed nicely. Finally, if it is an ideal instrument, it will contain a minimum number of parts, be easy to assemble, and require only minimal adjustment.

The prior art includes a plurality of configurations for a single adjusted venetian blind. Some of them are not inclined enough to provide good closure. Many of them are difficult to use and coordinate with a very large number of complex parts.

The prior art discloses two general methods of accumulating ascending cords or tapes on venetian blind headlines. One way is to wind the ascension cord or tape onto a spool. This method has two disadvantages. One disadvantage is that the cords or tapes do not wind evenly on their respective spools, and even very small diameter differences result in easily recognizable nonuniformities in the blinds when the blinds rise. Another disadvantage is that the mechanical advantage of the lifting mechanism decreases as the diameter of the cord or tape accumulated increases on the spool. The gradual reduction of this mechanical advantage occurs as the ascending cord requires more effort to raise the blind further supporting heavier blind weight. The mechanical advantage decreases at the very point where it should be improved.

Another preferred method is to accumulate the cord on a shaft that moves the cord laterally or laterally so that the ascending cord is wound in a single layer on the shaft. This method ensures uniform winding of each lift cord and maintains a certain mechanical advantage so that it is only increased in proportion to the weight supported by the lifting lift lift cord. Several methods have been used to traverse the rod. Rack and gear structures were used. U. S. Patent No. 1,343, 526 discloses leadscrews and nuts for achieving traversing. Another method without any gears or leadscrews has been found in US Pat. No. 4,625,012, in which a lifting cord acting on the cam structure of a supporting cradle generates lateral forces across the rod. Although this method is currently used to raise multiple blinds from the floor, the weight of the blinds suspended on the tilter was not expected to impose such a large friction force that the rod would not traverse properly. It is therefore not believed that the method can be applied to venetian blinds.

The headrail mechanism must also tilt the slide of the venetian blind. In a single adjusting blind which employs a traverising rod that accumulates the ascending cord, the inclined mechanism must be rotated in any direction along the traversing rod until a fully closed position is reached. Thereafter, the inclined mechanism should slip and maintain its position while the blind is rising or falling. In the transverse rod single adjustment venetian blind, the drive shaft for the tilt mechanism is the transverse rod. The ladder cord is attached to the inclined mechanism. In general, a single adjusting blind will have one tilt mechanism for the ladder cord in each of the blinds. When the ladder cord is separated like the dock of the slat and attached to the inclined mechanism, the optimum inclination is achieved. In addition, the line between these attachment points must pass through the centerline of the transverse rod. This keeps the inclination mechanism at the same angle as the slat. This geometric relationship is not maintained and the tilt mechanism must be able to raise the blinds when complete closure is achieved.

There is no difficulty in providing an inclined mechanism capable of raising the weight of the entire blind in a venetian blind having a separate rising mechanism and an inclined mechanism. However, in the cross rod unregulated blinds, the cross rod must drive both the tilt mechanism and the rise mechanism. When the full tilt position is reached, the tilt mechanism must partly slip off and then provide enough torque to maintain sufficient tilt as the rod continues to rotate to raise or lower the blind. Whatever force is needed to maintain sufficient inclination, it is added to the effort needed to raise the blind. This force is minimal when (a) the structure of the inclined mechanism is as described above and (b) the inclined mechanism can provide only the amount of torque necessary to adjust the gripping force on the transverse rod to maintain a sufficient inclination. Moreover, the less the separation of the two sides of the ladder cord at sufficient inclination, the better the closure. This last requirement is best met when the inclined mechanism is mounted directly on the transverse rod. Any intermediate part between the inclined mechanism and the rod will increase the separation of the ladder code during full tilt. U.S. Patent No. 4,697,630 discloses an inclined mechanism having a good gripping torque between both ends of the incline while partially releasing the gripping force upon reaching a full incline. The inclined mechanism is made in the form of a multiturn helical band clutch that grips the transverse rod during inclination. When a sufficient inclination position is reached, the tip of the inclination mechanism is in contact with the stop member, and the stop member prevents further movement of the inclination mechanism, thereby partially releasing the gripping force of the inclination mechanism on the rod. The frictional force is limited to the amount of torque required for the blind to maintain sufficiently inclined conditions. The rod continues to rotate to wind or unwind the ascending cord to raise or lower the blind according to the direction of rod rotation.

US Pat. Nos. 2,737,235, 2,758,644, and 3,352,349 describe prior art single-adjustment veneer blades employing a variety of transverse rod lift mechanisms. In order to achieve transverse motion in each of those prior art blinds, it is necessary to overcome all of the frictional forces due to the gravity of the blind acting on the transverse rod. The gripping force of the inclined mechanism of the transverse rod shall be sufficient to ensure complete closure. And, of course, both the warp force and the frictional force on the rod must be overcome to traverse the rod. These friction forces are large enough to make it very difficult to manipulate these blinds. Therefore, it is not surprising that venetian blinds using this type of instrument were not popular.

[Summary of invention]

A preferred feature of the helical band mechanism of US Pat. No. 4,696,630 can be combined with the transverse rod system according to US Pat. No. 4,623,012 to form a veneer rod that achieves a single adjustment operation and accumulates a rising cord in the head rail. This coupling has been attempted and the tilting mechanism imposes a frictional force on the transverse rod so large that it does not reliably traverse. The present invention provides a novel bearing device that removes most of this frictional force. In a preferred embodiment, the band clutch of US Pat. No. 4,697,630 is modified such that the inclination mechanism is directly supported by the cradle rather than by the transverse rod. This significantly reduces the frictional force on the transverse rods, thereby improving operational reliability. This blind has good closing properties and is easy to rise and fall. The blind has a small number of parts and is easy to assemble and adjust. The combination of the present invention has the advantages of both the inclined mechanism and the raised mechanism without the problem of sliding the rod against the large friction force found in the prior art blinds.

The use of a helical wrap band clutch inclination mechanism is one of the many known methods of driving the inclination mechanism of a single adjustment blind, if it is necessary during the inclination while maintaining the minimum range necessary to maintain sufficient inclination of the friction force between the inclination mechanism and the transverse rod. Another method of using frictional forces provides excessive frictional force to ensure good closure of the blinds, due to variations in frictional force. This surplus force is undesirably added to the blind opening force. U.S. Patent No. 3,352,349 discloses a single control venetian blind using a transverse rod and an inclined mechanism that grips the transverse rod with friction. The lifting cord carrier is arranged on the operating shaft 2 in a "slightly clamping way." However, experience has shown that the inclined mechanism must grip the operating shaft closely during the incline to close the blinds well, and this close grip requires the exertion of a large force by the traversing mechanism to slide the shaft.

In fully unfolded venetian blinds, the ladder cord supports the entire weight. As the blind is raised, the weight is transferred to the lift cord. When the blinds are fully raised, substantially the entire weight of the slat pack and the bottom rail is supported by the lifting cords. Since the ladder cord is attached to the inclined mechanism, anything supporting the inclined mechanism must also support the unfolded weight of the blind. Normal forces and the resulting friction between the inclined mechanism and its supports can make crossing difficult when the blind is about to be fully extended. At the same time, the inclined mechanism supports most of the gravity that generates the maximum friction, and the tension required to cause the transverse movement is at its minimum.

It is surprising that it is possible to generate sufficient inclined drive force without adding such a large friction force to the traverse mechanism to prevent the traverse. The reason why it is possible can be understood as follows. The force required to cause relative movement between two frictionally bonded objects is greater if the force acts only if the other force also causes movement, even if the movement is in the other direction. For example, referring to FIG. 1, the force F ₁ required to slide an object of weight W in the horizontal plane is equal to μW when the friction coefficient between the object and the horizontal plane is μ. However, if an object moves under the action of two normal forces F ₁ and F ₂ , then such as μW is the sum of F ₁ and F ₂ vectors, as shown in Figure 2, where A is the actual direction of movement and F _Is an angle between _two . In this state, both F ₁ and F ₂ are smaller than μW, and if angle A is small, F ₁ is much smaller than μW.

In the present invention, F ₂ corresponds to the force for rotating the rod to forcibly slip the rod in the inclined mechanism, and F ₁ corresponds to the force required to traverse the rod. In a representative embodiment of the present invention, a 0.375 inch diameter rod and a rising cord of about 0.040 inch were used. Since the rod makes one complete turn while traversing only a distance equal to the thickness of the cord, the surface movement in the rotational direction makes the angle A a very small angle, slightly less than 2 degrees, about 30 times the transverse movement. . In this case, the force F ₂ , which causes the rotational motion, does most of the work against friction, and F ₁ is only about 3% of what is needed to cause transverse movement in the absence of F ₂ . For blinds with intermediate parts between the inclined mechanism and the drum, a sufficient amount of work must be done at both the blind interface between the inclined mechanism and the drum and between the drum and the rod. The whole amount of work must be provided by the blind operator, which significantly increases the force required to manipulate the blind.

For very long blinds it has proved necessary to use the inclined mechanism of US Pat. No. 4,697,630 to add weight to the bottom rail to ensure that the transverse rod is fully returned to its starting position. In a preferred embodiment of the invention, improvements are made by deforming the inclined mechanism and the cradle such that the inclined mechanism is directly supported by the bearing surface on the cradle rather than by the transverse rod. The improved performance is due to the reduction in the daily force between the rod and the tilt mechanism. In previous systems, the force required to cause lateral movement has increased as the force available to cause that lateral movement decreases. Here, the force available to cause lateral movement when the blind descends is still reduced, but the force that hinders the lateral movement of the rod remains constant and small.

It is therefore an object of the present invention to provide a single adjustable raised ramp mechanism for venetian blinds that requires minimal force to operate and maintains a constant mechanical advantage during the rise.

Another object of the present invention is to provide a single adjustment lift and ramp mechanism for venetian blinds that requires less maneuverability for heavy and long blinds.

It is a further object of the present invention to provide a single adjustable lift and ramp mechanism for venetian blinds that can raise the long blind of a relatively small headrail.

It is another object of the present invention to provide a single adjustable lift and ramp mechanism for venetian blinds that can apply sufficient torque to ensure good closure.

It is a further object of the present invention to provide a single adjustable lift and ramp mechanism for venetian blinds that allows for closed alignment of the ladder cord in a sufficient tilted position.

It is still another object of the present invention to provide a single adjustable lift and ramp mechanism for venetian blinds without the need for the full torque required for the amount of ramp during the rise of the blind.

Again, another object of the present invention is to provide a single adjustment lift and ramp mechanism for venetian blinds with a minimum number of parts that is easy to assemble and can be easily adjusted for proper operation.

Detailed Description of the Drawings

In figure 3 the overall configuration of the lifting system in the headrail can be seen. The headrail 1 can be of any conventional cross-sectional shape with sufficient internal space to accommodate the hardware. The holding mechanism 3, which can be any of a wide variety of devices, may be mounted at the end of the head rail 1, although other positions are possible. In order to operate the holding mechanism 3 some suitable means of operation are required. In this case, the code loop 5 is shown, although any of the different combinations of holding mechanisms and actuation means can be used instead. The spline 7 is attached to the output of the holding mechanism 3. The spline 7 together with the disk 9 attached to the transverse rod 11 form a connection for torque transmission which is axially slideable between the holding mechanism 3 and the transverse rod 11. The particular spline and disk device shown here for connecting the holding mechanism is merely exemplary and other means for establishing the connection can be used without departing from the scope of the present invention.

The remaining parts in the headrail relate to the attachment, adjustment and operation of the lifting cord 13 and the ladder cord 15. One such set is normally installed in the lift and ladder code sets, respectively. Moving parts, forces, and actuations are described for one set of these lifting and tilting elements, and the description is intended to apply to the other set. In some blinds, some set of elements may be used in one or more locations. For example, blinds often have three ladder codes and only two rising codes. This is the case when two ascending cords are sufficient for blind rise and the center ladder cord is necessary to properly support the slats. In such a case, the operation of the blinds remains the same as it relates to an incomplete set of elements.

Cradle 17 and inclined mechanism 19 are generally disposed in accordance with the principles of US Pat. No. 4,697,630. Each side of the ladder cord 15 is attached to one of the two arms 21 of the inclined mechanism 19 as best shown in FIG. The lifting cord 13 is generally arranged according to the principle of US Pat. No. 4,623,012, where the head rail is introduced through the hold of the rail bottom, passing through the roller 23 as shown in FIG. , At the point where it is attached to the rod 11 by a clip 25 or some other suitable means.

5 shows a prior art assembly with a helical band tilting mechanism according to the principle of US Pat. No. 4,697,630 of a transverse rod elevating system according to the principle of US Pat. No. 4,623,012. The transverse rod 27 is directly supported by the cradle 29 whose support surface is shaped to receive the rod 27. The inclination mechanism 33 is entirely supported around the rod 27. 6 shows the inclined and raised elements of the invention with the slats in the horizontal position. In this figure, the arm 21, which is shown in FIG. 4 but is removed in FIG. 5, is placed in a horizontal plane passing through the center of the rod 35 for clarity. The inclined mechanism 37 is wound around the rod 35 as in the previous embodiment, but in this case, the inclined mechanism has a bearing 39 supported on the support surface 41 on the cradle 43. The flange 45 at the end of the inclination mechanism 37 forms a retaining barrier along the rod 35 to prevent axial movement of the inclination mechanism 37 in relation to the cradle 43. The outer surface of the flange 45 is angled to form the cam surface 47 in accordance with the principles of US Pat. No. 4,623,012. The outer surface of the flange 45 is angled to form the cam surface 47 according to the principle of US Pat. No. 4,623,012. The angle is equal to the angle A shown in FIG. The preferred size of the angle A depends on the ratio of the diameter of the ascending cord 47 to the diameter of the rod. It is necessary to provide a space for the introductory code so that sufficient movement is caused by the cam action so that the introducing code does not ride on the preceding ground. If the blinds are sufficiently lowered and most of the weight is suspended on several blind ladder cords, very little blind weight is supported at the surface between the rod 35 and the inclined mechanism 37. Instead, most of the weight is supported at the support surface 41 between the cradle 35 and the ramps 37. This reduction in friction between the inclined mechanism and the transverse rod allows the rod to move much more easily. By this improved method of support of the inclined mechanism 37, much less tension is required on the ascending cord 40 to ensure that the transverse rod 37 returns to its initial position upon complete lowering of the blind.

FIG. 7 shows elements as shown in FIG. 6 during the rise of the blinds. As the lifting cord 49 is wound on the rod 35, the lifting cord 49 is axially moved to the cam surface 47 to move the rod 35 laterally away from the cam surface to the left. The inclination mechanism 37 is sufficiently rotated to the limit allowed by the stop member 51 to loosen the gripping force of the inclination mechanism 36 on the rod 35 to maintain the gripping force sufficient to maintain its direction. In this position, the arm 53 is approximately vertical, so that several ladder cords visible to only one adjacent ladder cord 55 are in a sufficiently inclined position.

The mechanism of US Pat. No. 4,632,012 does not have a tilt mechanism. The cam surface is formed as part of the cradle. In the present invention, the cord is in contact with the inclined mechanism flange. Therefore, it is essential to incorporate the cam surface into this flange. One of the features of the blinds of the present invention is that it can be raised in any direction as the rod is rotated. This requires that the cam surface is on the right when the blind is raised by counterclockwise rotation of the rod and on the left when the rod is rotated in the opposite direction. When the blind is raised, the tilt mechanism rotates 90 degrees in the direction of rotation of the rod. This properly orients the cam surface 47 with respect to the winding direction of the rising cord. The cam action occurs at an arc circumference of about 120 degrees between the point where the cord first contacts the shaft and the top of the shaft. As shown in FIG. 6, the cam surface 47 occupies the lower portion of the flange 45 when the inclination mechanism 37 is horizontal. As the tilt mechanism rotates 90 degrees in one or the other, the cam surface rotates in the required direction.

In another preferred embodiment of the present invention, the tilt mechanism is supported directly by the cradle rather than by an actuating rod which in this case does not move laterally but merely rotates. In this type of uni-adjusted blind, the rise is achieved by winding the tape or cord onto the spool. This type of blind does not have a transverse rod, but in reducing actuation friction even a tool made several times to achieve a small improvement in the operating "feel" of a blind made of this structure is achieved. To replace, it leaves a serious problem that requires considerable effort. FIG. 8 shows the rising and tilting elements of the present embodiment corresponding to the elements of the illustrated preferred embodiment of FIGS. 5 and 6. The rod 57 has a tilt mechanism 59 disposed around it. The inclined mechanism 56 has a support groove 61 which is supported and rotated on the support surface 63 of the cradle 65. The cradle 65 has a cradle 37 of the preferred embodiment except that it has a slot 67 for guiding the cord or tape 69 on the spool 71 instead of a roller for guiding the rising cord. similar. In this case, since there is no transverse movement of the rod, the spool 71 is firmly attached to the rod 57 and rotates with it. As in the previous case, the inclination mechanism 59 must rotate with the rod 57 until it reaches its stop. Thereafter, the inclination mechanism must be held in place to maintain sufficient inclination while the rod 5 continues to rotate therein to raise or lower the blind. In this case, it is important to adjust the frictional force to ensure that there is sufficient gripping force of the inclined mechanism on the rod 57 to generate a sufficient inclination. However, the additional frictional force between these parts only adds blind actuation force. Significantly reducing the operating force is achieved by moving the support load from the rod 57 to the support surface 63 of the cradle 65. In this embodiment, the cam surface is not necessary because the rod does not move laterally, and has an outer surface perpendicular to the axis of the rod 57 of the flange 73 of the inclination mechanism 59.

Therefore, as will be apparent from the foregoing description, the objects of the foregoing description are effectively achieved, and all contents contained in the foregoing description of the invention and shown in the accompanying drawings without departing from the spirit and scope of the invention are illustrative rather than limiting. It will be understood that it should be interpreted as.

In addition, it is to be understood that the following claims are, by language, comprehensive of all descriptions of the general and specific features of the invention and the scope of the invention which may fall within the scope.

Claims (14)

A single adjustable ramp system assembly for venetian blinds, comprising: a transverse rod rotatable in two directions along an axis, at least one multi-turn helical ramp member gripping the rod and attached to a ladder cord of the blind, in any direction of rotation A relaxation means for at least partially loosening the inclined member relative to the rod at a position corresponding to a sufficient inclination, at least one lifting cord attached to the rod and wound or unwound on the rod in response to the rotation of the rod, Means for applying a first lateral force to the transverse rod as the cord is wound around the cross rod, at least one surface substantially disposed at a point where the at least one ascending cord attaches to the rod, and friction on the rod Having a surface for supporting the inclined member to reduce drag Even a single Venetian blind adjusting the inclination and rise system which is characterized in that it comprises the transverse load support means having a cradle. 2. A system according to claim 1, wherein said relaxation means comprises restraining means for limiting rotational movement of said inclined member in said sufficient inclined position. 3. The system according to claim 2, wherein said restraining means comprises at least one stop member for releasing the gripping force of said inclined member on said rod at said sufficient inclined position. The system of claim 1, wherein the at least one inclined member has a central portion configured to hold a rod and two arms for receiving an end of the ladder cord. The system of claim 1 wherein said at least one inclined member is flexible. The system of claim 1, wherein the background of the at least one inclined member is substantially the same as the outer diameter of the rod such that the at least one inclined member is tightened around the rod by the gravity of the venetian blind. The system of claim 1, wherein the at least one inclined member is mounted directly on the rod without any intermediate member. The system of claim 1 wherein the cradle includes an opening through which the ladder code passes. The system of claim 1, wherein the means for applying the lateral force includes a cam surface, the lifting code being supported on the cam surface to allow the rod to move laterally in the first lateral direction. . 10. The system according to claim 9, wherein the cam surface is configured to move the rod laterally by rotation of the transverse rod winding the lifting cord around it. 11. The system of claim 10, wherein the cam surface is configured such that the ascending cord is wound onto the rod in a monolayer upon rotation of the rod. The system of claim 1, wherein the at least one helical member has a protruding flange that maintains an axial position of the helical member relative to the cradle member. 13. The system of claim 12, wherein the flange has a cam surface, the surface of which is supported by the rising cord to allow the cord to move laterally. 14. The system of claim 13, wherein the cam surface of the flange is disposed at an angle dependent on the dimensions of the rod and lift cord.