Field and Background

[001] The present invention relates to the field of roller shutters. More specifically, to a field of locking curtain of a roller shutter, preventing the opening of the curtain by pushing it up from outside.

Summary of The Invention

[002] Roller shutters can be opened from the outside by elevating the slats. Regarding to roller shutters, this possibility is a security lack. The present invention provides a lock that can be used for locking the curtain of a roller shutter and prevents the ability to push the slats up and open the curtain.

[003] The present invention is a lock, for locking the curtain of a roller shutter. According to the present invention, the lock is comprised of (a) a lock-tongue, installed on an end of a slat of the curtain and projected from the edge of this slat, in direction to the sidewall or to the curtain rail. The lock-tongue moves up and down with the slat; and (b) a locking system.

[004] The above mentioned locking system is comprised of (i) a housing to be installed either inside the rail in which the curtain is running up and down or on outside of this rail or on the wall beside die rad, in the same side where die lock-tongue is installed The housing has a side opening in direction to the lock-tongue; (ii) two racks and pinions and a spring, installed - on top of each other - inside the housing, between the bottom and the roof; each pinion is pivotally installed on an axis between the walls of the housing; a lower rack and pinion having an arm horizontally projected from the center of die pinion to outside of the housing through its opening, an upper rack and pinion -located upon the lower rack and pinion - having two arms - the first arm is horizontally projected from the center of the pinion to outside of the housing through its opening and the second arm is vertical to the first arm - and the spring is installed between the top of the upper rack and the roof of the housing; and (iii) a spring stopper, located behind tiie lower edge of the lower rack, in order to hold the lower rack up after it was elevated and to release it by a small threshold power down.

[005] In order to lock the curtain, the lock-tongue moves down with the curtain and is arrived to the locking system, the lock-tongue pushes the horizontal arm of the upper pinion down and elevates its upper rack, when the lock-tongue passes the horizontal arm, the spring pushes back the upper rack that returns back the horizontal arm. This horizontal arm blocks the movement back up of the lock-tongue since the upper rack is blocked by the lower rack and therefore the clockwise rotation of the upper pinion is disabled. The shutter's motor is programmed to stop the curtain at this point and the curtain is locked.

[006] In order to release the lock-tongue, to enable the curtain to move back up, the shutter's motor drives the curtain down for a while until the lock-tongue pushes the horizontal projected arm of the lower rack and pinion. The lower rack is elevated and is held up by the spring stopper. The lower rack pushes up the upper rack that rotates the upper pinion to a position that both arms of the upper rack and pinion were rotated anticlockwise by 90 degrees. Then the motor drives the curtain up with the lock-tongue, which pushes the second projected arm of the upper rack and pinion and rotates the pinion back to its original position while pushing both racks down with a power that releases the spring stopper. Now the curtain can continue to move up. [007] According to a preferred embodiment, the lock is installed on a roller shutter, wherein the motor of the roller shutter is programmed to stop the curtain after the lock-tongue pass the projected arm of the upper rack and pinion in order to lock the curtain. And, in order to release the curtain the motor is programmed to drive the curtain down for a while until the lock-tongue passed the projected arm of the lower rack and pinion, then the motor drives the curtain up.

[008] According to another preferred embodiment, the lock is provided, wherein the lock-tongue is done by adding to the curtain - or replacing an existing one - a longer slat that is projected aside and is used as a lock-tongue.

Brief Description of The Drawings

[009] Various other features and attendant advantages of the present invention will be more fully appreciated from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views, and wherein:

Figure 1 illustrates step 1 - the locking system and the lock tongue, before locking.

Figure 2 illustrates step 2 - the lock tongue is locked.

Figures 3 illustrates step 3 - moving down for releasing the curtain.

Figure 4 illustrates step 4 - moving up, and the curtain is released.

Detailed Description of The Preferred Embodiments [010] The principles and operation of the lock for locking the curtain of a roller shutter, according to the present invention, may be better understood with reference to the drawing and the accompanying description.

[Oil] The present invention is a lock, for locking the curtain of a roller shutter, Figure 1 illustrates step 1 - the locking system and the lock- tongue, before locking. The figure illustrates a cross section of the locking system (10), which is comprised of a housing (16) in which are installed - on top of each other - a lower rack (12) and pinion (15) with an arm ( 15a) projected from the center of the pinion (15) horizontally out of the housing (16), an upper rack (1 1) and pinion (14) with two arms (14a&14b) - first arm (14a) is projected from the center of the upper pinion (14) outside od the housing (16) and second arm (14b) vertically from the center of the upper pinion (14). Between the top of the upper rack (11) and the roof of the housing (16) a spring (13) is installed.

[012] the figure also illustrated the relevant part (20) of the curtain, the edge of a slat (21) and a lock-tongue (22) that is projected from the slat (21) in direction to the locking system (10). In order to lock the curtain the locking system (10) is designed to lock the lock-tongue (22).

[013] Figure 2 illustrates step 2 - the lock-tongue is locked. The curtain moved down with the slat and the lock- tongue (21&22), from their previous position (20a). During its movement down, the lock-tongue (22) pushed down the first arm (14a) that rotated the upper pinion (14) that elevated the upper rack (1 1). The lock- tongue (22) continue to move down for a while and the first arm (14a) is released, enabling the spring (13) to push back the upper rack (1 1) that rotates back the upper pinion (14) with the first arm (14a). Finally, the first arm (14a) with the upper pinion (14) rotated anticlockwise and clockwise (14m) and the upper rack (1 1) moved up and down (1 lm). In this position the upper rack (11) unable to move down due to the blocking of the lower rack (12) and accordingly the firs arm (14a) cannot move up and therefore it blocks the lock-tongue (22), which now it is below the first arm (14a), and the curtain is locked.

[014] Figures 3 illustrates step 3 - moving down for releasing the curtain. In order to release the curtain - and unfolded it up - the shutter's motor drives the curtain down for a while and then up. This figure illustrates the step of the moving down.

[015] in this step, the slat (21) with the lock-tongue (22) were moved down from their previous location (20a). In this movement the lock-tongue (22) pushes down the arm ( 15a) of the lower rack and pinion ( 12 & 15) that rotates the lower pinion (15) anticlockwise (15m) that elevates the lower rack (12) that pushes up the upper rack (11). Both racks ( 1 1 & 12) are moved up ( 13m) against the spring (13), but are held up by the spring stopper (17). Accordingly, the upper pinion (14) and its both arms (14a&14b) were rotated anticlockwise (14m), then the shutter's motor starts to drive the curtain up.

[016] Figure 4 illustrates step 4 - moving up and the curtain is released. In this step, the slat with the lock- tongue (21&22) were moved up from their previous location (20a). On the way up, the lock-tongue (22) pushes the second arm (14b) of the upper pinion (14) and rotates clockwise (14m) the upper pinion (14) with its both arms (14a&14b).

[017] The rotation of the upper pinion (14) with the help of the spring (13) were released the held of the spring stopper (17) and both racks (11&12) were moved down (1 lm). The movement of the lower rack (12) rotates the lower pinion (15) with its arm (15a) clockwise (15m) to their original position. The curtain now can be driven up. [018] Now the locking system (10) returns to its original position and ready to lock again.

[019] In order to use this lock, the motor of the shutter should be programmed to stop the curtain when the lock-tongue is arrived to the locking system and for releasing the curtain and unfold it the motor should be programmed to move a while down first and then to move up.