Patent Application
20060113045
This invention relates to shutter mechanisms for closing openings such as garage doors and shop windows, and more particularly to shutters with a plurality of parallel bars or blades and motion screw.
A common type of shutter mechanism for closing a door opening comprises a plurality of shutter members such as parallel plates or blades extending across the opening and movably mounted to opposite sides thereof. In a closed position of the shutter, the blades lie generally in the plane of the opening, with touching or overlapping edges, thereby closing the opening. In an open position of the shutter, the blades are removed from the opening and may be stacked one over the other or collapsed face-to-face or rolled in a roll or just drawn away along the ceiling or a wall, etc. as the design may be. The transition from closed to open position and back is performed by a motion device that may employ pulleys and ropes or chains, scissors lever mechanism, motion screw, etc. and a motor or manual drive. Another common type of shutter has a number of parallel bars connected with transverse elements such as diagonal cross-bars moveable like scissors, or flexible chains, bands, etc. so that these elements obstruct the passage when the parallel bars are in the most spaced position.
For example, U.S. Pat. No. 5,163,494 discloses a sectional door installation comprising a series of horizontal blades mounted with their opposite ends to scissors linkages. The lowermost linkage is raised or lowered by an endless chain whereby all linkages contract or extend simultaneously. The blades are mounted to one of the two levers in a scissors pair and turn together with the lever, so that in the most raised position, the blades are nearly horizontal and are stacked in a tight stack under the upper beam of the doorframe.
U.S. Pat. No. 5,469,905 describes a security and hurricane shutter using blades which are longitudinally pivoted to each other. Every other pivoting axis is supported in a vertical guide at the two opposing sides of the door. The shutter can use either pulleys or motion screw that raises the lowermost blade. Thereby, the whole blade assembly collapses like accordion towards the upper beam of the door.
U.S. Pat. No. 4,846,244 discloses a window shutter comprising a plurality of horizontal blades, a tilting device for simultaneously tilting all the blades about their horizontal axes, and a raising device. The blades are mounted on shafts received within channels at opposite sides of the window. The devices for tilting and raising of the blades employ ropes and pulleys like in Venetian blinds.
The usage of motion screws in shutter mechanisms generally allows more accurate motion than the usage of ropes or chains. However, the stacking of the blades in known shutter mechanisms requires that only one blade is engaged with the screw thread thus overloading this blade while the other blades lose the accuracy of motion.
In accordance with the present invention, there is provided a stacking mechanism for shutter members of a shutter mechanism comprising:
The traveling nuts are arranged at intervals W1i, i=1, 2, . . . , N−1, preferably uniform, within the length L1 in a first position of the mechanism. By means of continuous rotation of the screw in one direction, they can slide along the screw within the length L1 at rate P1 per 1 turn of the screw under the action of the arrester and the thread with pitch P1. The nuts can transit smoothly and reversibly from L1 to L2, and can slide with rotation along the screw within the length L2 at a rate P2 per 1 turn of the traveling nut under the action of the thread with pitch P1 and the thread with pitch P2. The nuts can achieve reversibly a second position of the mechanism where they are arranged at intervals W2i, i=1, 2, . . . , N−1 within the length L2, where W2i<W1i and L2<L1.
Preferably, the arrester is an elongated member, i.e. an L or C-profile, parallel to the screw, and the traveling nuts have a notch engaging the elongated member while the traveling nuts are within the length L1.
Each traveling nut has a connection element mounted for free rotation about the nut axis and carrying a non-rotating shutter member. The connection element is preferably a ring with an inward rim and a radial pin while the nut has an external annular channel adapted to engage the inward rim.
The threaded member has a cutout parallel to the thread axis so that the connection elements can travel together with the traveling nuts within the length L2. The threaded member may be a toothed rack parallel to the screw, the teeth of the rack constituting thread with pitch P2.
According to another aspect of the present invention, there is provided a shutter mechanism for closing an access aperture, comprising two stacking mechanisms as described above. The stacking mechanisms are disposed parallel to each other at two opposite sides of the access aperture with their threaded members at a third side of the aperture (“stacking side”), their N×2 traveling nuts in symmetric disposition, and their screws adapted for synchronous rotation.
The shutter mechanism further comprises a plurality of N shutter members extending between the stacking mechanisms perpendicularly to their screws, each connected to a pair of connection elements. The shutter members are distributed over the access aperture in the first position of the stacking mechanisms, whereby the access aperture is closed. The shutter members are stacked at the stacking side in the second position of the stacking mechanisms, whereby the access aperture is opened.
In one embodiment of the present invention, the shutter members are flat rectangular blades with long edges and short edges. Each blade is connected to the pair of connection elements by its short edges so that it can swivel about an axis defined by this pair. The blades are disposed approximately in one common plane in the first position of the stacking mechanisms, and are turned away from this common plane in the second position of the stacking mechanisms.
The shutter mechanism further has a pivoting mechanism adapted to swivel each blade away from the common plane before the traveling nuts connected to the blade start their transition from the length L1 to the length L2.
The pivoting mechanism comprises:
In a first embodiment of the pivoting mechanism, the pivoting means is a curved portion of the guiding means adapted to catch for a while the free end of one of the pivoting levers and allow a transverse motion of the free end when the respective blade travels past the curved portion, whereby the pivoting lever turns the respective blade.
The pivoting mechanism may be adapted to swivel all blades away from said common plane simultaneously, before the nearest traveling nut starts its transition from the length L1 to the length L2. In a second embodiment of the pivoting mechanism, the pivoting means is an assembly comprising a movable suspension of the guiding member adapted to displace the guiding member from its initial position transversely to the screw, while preserving the parallel orientation and the engagement with the roller. The pivoting assembly further comprises a latch preventing the displacement of the guiding member when in locked position, an actuator engaged with the screw and adapted to unlock and lock the latch in predetermined positions relative to the screw, a plurality of traps associated with the guiding member and adapted to catch for a while the free end of the lever of each blade when the free end contacts the trap.
All the above members and elements are disposed in such way that, in the process of screw rotation, starting from the first position of the stacking mechanism, the following takes place in succession: the traveling nuts together with the blades and their levers start moving from the length L1 to the length L2, the actuator unlocks the latch and thereby the guiding members, the free ends of the levers are simultaneously caught by their respective trap means, the movable suspension displaces the guiding member from its initial position, the levers turn about their caught free ends and turn the blades away from the common plane, the guiding member returns to its initial position, the free ends are released from their trap, the actuator locks the latch and thereby the guiding members, the nuts and the blades in position away from the common plane continue moving to the length L2.
In a second embodiment of the present invention—a bar-shutter mechanism—the shutter members are elongated bars. A plurality of movable elements connects each two adjacent bars so as to obstruct the passage between the adjacent bars in the first position of the stacking mechanisms (closed position).
In one embodiment of the bar-shutter mechanism, the moveable elements are short slats with one end rotatably mounted to one bar and a second end mounted slidingly and rotatably to the adjacent bar. The moveable elements may be also flexible, such as chains, ropes, mesh, textile, elastic sheets, etc.
The stacking mechanism and the shutter mechanism of the present invention provide for a very accurate and reliable motion of the shutter members. Shutter blades may abut very accurately and tightly in the closed position of the shutter, while fitting in a compact stack in the opened position of the shutter. The traction force is distributed uniformly and simultaneously to all shutter members. The parts and assemblies of the mechanism are robust and sturdy. The construction excludes any possibility of bar or blade misalignment in operation, jamming, locking or seizure of the moving parts.
In order to understand the invention and to see how it may be carried out in practice, preferred embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
With reference to
The stacking mechanism and the construction of the whole shutter mechanism are described in greater detail in the following figures. With reference to
The screw 22 has length L and its thread 24 is multi-start thread with pitch P1 (one turn thereof is shown under number 24′).
With reference also to
The arrester 28 is an elongated member with C-like cross-section, of length L1 disposed parallel to the screw. The sides 56 of the C-section engage the notches 40 and 41 of the nut 26, as shown in
The treaded member 30 is formed as a tooth rack parallel to the screw 22, the teeth constituting the internal thread 32 with pitch P2, matching the thread 38 on the nut 26. The member 32 has length L2 and is disposed adjacent the arrester 28.
The stacking mechanism 20 operates as follows. With initial position of the traveling nut 26′ within the length L1 of the screw, the screw 22 starts uniform rotation in one direction. Within the length L1, the traveling nut 26 is engaged with the arrester 28 by means of the tooth 44 and notches 40 and 41 which prevents the i5 rotation of the nut. Therefore, the nut slides along the screw 22 at rate l1=P1 per 1 turn of the screw. When the traveling nut 26 reaches the end of the arrester 28 at the boundary between lengths L1 and L2, the tooth 44 disengages from the arrester 28. At the same time, the tooth 44 abuts the start of the thread in the threaded member 30 which stops the sliding of the nut along the screw 22. But now the nut 26 is able to rotate together with the screw 22, the tooth 44 and the whole thread 38 following the internal thread 32. Therefore, when within the length L2, the nut performs a complex motion including rotation with the screw 22 but with angular sliding, and linear translation at rate P2 per 1 turn of the nut. The linear travel 12 of the nut per one turn of the screw is:
l2=(P1×P2))/(P1+P2)
Upon reverse rotation of the screw, the nut travels back from the length L2 to the length L1 with smooth transition. It will be readily appreciated that if two nuts 26 are positioned initially at a distance W1 on the length L1 of the screw 22, after both nuts pass over to the length L2, they will be positioned at a distance W2:
W2=(W1×P2)/(P1+P2)
With reference also to
The stacking mechanism of the present invention is advantageously used in the shutter mechanism 10 shown externally in
The shutter mechanism 10 further comprises a plurality of N flat rectangular blades 12 with long edges 14, short edges 16 of width W1, and thickness T<W2. The short and long edges of the blades are disposed approximately in one common plane (the plane of the aperture) in the first position of the stacking mechanisms, as shown by blades 12B and 12C, whereby the access aperture is closed. The blades are stacked under the upper beam 59, turned perpendicularly to the common plane, in the second position of the stacking mechanisms, as shown by blade 12′, whereby the access aperture is opened.
With reference also to
With reference also to
a) N pivoting levers 72, each one firmly mounted to one short edge 16 of each blade, generally in a plane perpendicular to the blade axis. Each lever 72 has a roller 74 at its free end 76;
b) A guiding member 78 extending parallel to the screw 22. The guiding member 78 has a channel profile (C-shaped cross-section) which engages the roller of each pivoting lever while the blade is traveling along the screw;
c) A movable suspension (not shown) of the guiding member allowing the guiding member to be displaced from its initial position transversely to the screw, while preserving the parallel orientation and the engagement with the roller;
d) A latch 82 preventing the displacement of the guiding member 78 and disposed at the lower end of the guiding member;
e) an actuator 84 engaged with the screw 22 and adapted to unlock and lock the latch 82. The actuator 84 is actually a traveling nut 26T that carries a finger 85 adapted to engage the latch 82 when moving past the latch.
f) A plurality of N traps 88 (recesses) disposed on the guiding member 78 at intervals W1. The traps 88 are adapted to catch for a while the free end of the lever of each blade when its roller falls into the trap.
The shutter mechanism 10 operates in the following way. In the first position of the stacking mechanism (
During the upward motion, the rollers 74 successively fall into next traps 88 but the actuator 84 cannot engage the latch anymore. Therefore, the rollers 74 are pulled out without turning the levers 72.
It should be appreciated that in the reverse (downward) motion, the operation proceeds exactly in the reverse order.
The pivoting mechanism may be adapted to swivel each blade away from the common plane just before its traveling nuts start their transition from the length L1 to the length L2. A second embodiment of the pivoting mechanism shown in
Another application of the stacking mechanism is shown in
In the first position (
It would be appreciated that elements which extend between the bars 112 may be of various nature, such as flexible chains, ropes, mesh, textile, elastic sheets, etc.
Although a description of specific embodiments has been presented, it is contemplated that various changes could be made without deviating from the scope of the present invention. For example, the present invention could be modified and used with gates, windows, awnings, blinds and other kinds of closures where precise motion and reliable closing is needed. The shutter mechanisms may be mounted with vertical screws, with horizontal screws and in any orientation of the access aperture plane.
| Number | Date | Country | Kind |
|---|---|---|---|
| 154223 | Jan 2003 | IL | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IL04/00039 | 1/15/2004 | WO | 7/26/2005 |
