WOLEK, Jerzy (Kalno 51, 58-130 Zarow, PL)
| Patent claims 1. Mechanism blocking the rotation of roller blinds winding roller with a spring drive, specially a window blinds, immovably fixed to roller blinds holder and its winding roller, characteristic that it is built from a sleeve (1) with cams (2a), (2b), (2c), (2d) formed on its inner side and in the sleeve (1) there is located a roller (3) with a guide (4) as an oblong groove, formed above the cams (2a), (2b), (2c), (2d) on its cylindrical side and in the guide there is a ball (5) which during revolution of the roller (3) against the sleeve (1), depending on the direction of that rotation, is moved between the cams (2a), (2b), (2c), (2d) or blocked in a pocket (2e) formed in the cam (2b) in positions from I to IV5 blocking or releasing relative revolution of the roller (3) and the sleeve (1) 2. Mechanism according to claim 1, characteristic that on the sleeve (1) there are formed two pairs of cams (2a), cams (2b), offset one against another with 180° with a formed pocket (2e), cams (2c) and cams (2d). 3. Mechanism according to claim 1 or 2, characteristic that sleeve (1) is joint to winding roller and roller (3) is joint to roller blinds holder. 4. Mechanism according to claim 1 or 2, characteristic that sleeve (1) is joint to roller blinds holder and roller (3) is joint to winding roller. 5. Mechanism blocking the rotation of roller blinds winding roller with a spring drive, specially a window blinds, immovably fixed to roller blinds holder and its winding roller, characteristic that it is built from roller (3) with cams (2a), (2b), (2c), (2d) formed on its cylindrical side and on the roller (3) there is seated a sleeve (1) with a guide (4) as an oblong groove, formed above the cams (2a), (2b), (2c), (2d) on its cylindrical side and in the guide there is a ball (5) which during revolution of the roller (3) against the sleeve (1), depending on the direction of that rotation, is moved between the cams (2a), (2b), (2c), (2d) or blocked in a pocket (2e) formed in the cam (2b) in positions from I to IV, blocking or releasing relative revolution of the roller (3) and the sleeve (1). 6. Mechanism according to claim 5, characteristic that on the roller (3) there are formed two pairs of cams (2a), cams (2b), offset one against another with 180° with a formed pocket (2e), cams (2c) and cams (2d). 7. Mechanism according to claim 5 or 6, characteristic that sleeve (1) is joint to winding roller and roller (3) is joint to roller blinds holder. 8. Mechanism according to claim 5 or 6, characteristic that sleeve (1) is joint to roller blinds holder and roller (3) is joint to winding roller. |
The subject of invention is a mechanism blocking the rotation of roller blinds winding roller with a spring drive, specially a window blinds, used to block the sunshade in its set position of unwinding.
In rolling mechanisms there is often used a spring drive to pull in i.e. to lift and stretch the sunshade in the direction of winding. To keep the sunshade in a desired position of unwinding, blocking mechanisms are used. Exemplary mechanism blocking the sunshade in a desired position are known from patent specifications No. EP 044134; WO 91/03619 and US 4534396. Blocking mechanism is usually embedded into roller blinds' structure. In such designs, after the sunshade had been unrolled from the roller, it is blocked in its lower position.
From patent abstracts No. US 4372432 and US 5375643 it is known a helical spring partly wound round a plastic part. This solution is simpler design-wise than other known solutions although dimensional tolerances of the spring and of the plastic part do not allow to achieve a satisfactory design.
Mechanism blocking the rotation of roller blinds winding roller with a spring drive, specially a window blinds, immovably fixed to roller blinds holder and its winding roller, according to the invention is characterized by the fact that it is built from a sleeve with cams formed on its inner side, in that sleeve there is located a roller with a guide as an oblong groove, formed above the cams on its cylindrical side. In the guide there is a ball which during revolution of the roller against the sleeve, depending on the direction of that rotation, is moved between the cams or blocked in a pocket formed in the cam in positions from I to IV, blocking or releasing relative revolution of the roller and the sleeve.
Advantageously on the sleeve there are formed two pairs of cams, of the same shape, offset one against another with 180° on the surface of the sleeve.
Advantageously the sleeve is joint to the winding roller and the roller is joint to roller blinds holder.
Advantageously the sleeve is joint to roller blinds holder and the roller is joint to the winding roller of roller blinds.
Mechanism blocking the rotation of roller blinds winding roller with a spring drive, specially a window blinds, immovably fixed to roller blinds holder and its winding roller, according to a different form of the invention is characterized by the fact, that it is built from a roller with cams formed on its cylindrical side, on which a sleeve is seated, on cylindrical side of that sleeve, above the cams, there is formed a guide as an oblong groove. In the guide there is a ball which during revolution of the roller against the sleeve, depending on the direction of that revolution, is moved between the cams or blocked in a pocket formed in the cam in positions from ϊ to IV, blocking or releasing relative revolution of the roller and the sleeve.
Advantageously on the roller there are formed two pairs of cams, of the same shape, offset one against another with 180° on the surface of the roller.
Advantageously the sleeve is joint to the winding roller and the roller is joint to roller blinds holder.
Advantageously the sleeve is joint to roller blinds holder and the roller is joint to the winding roller of roller blinds.
The advantage of the invention is design-wise simple solution allowing for reliable blocking of winding roller against roller blinds holders in different positions of unrolled sunshade, being wound onto winding roller.
The subject of invention is shown as example of realization, where fig. 1 presents longitudinal section of the blocking mechanism, fig. 2 presents unfold view of the sleeve surface with the cams from fig. 1, fig. 3 presents longitudinal section of mechanism in the second example of realization, fig. 4 presents unfold view of the roller surface with the cams from fig. 3, fig. 5 presents unfold view of the roller surface or of the sleeve surface in another example of realization.
Blocking mechanism immovably fixed to roller blinds holder and its winding roller, on which the sunshade is wound up, consists of sleeve 1 in which cams 2a, 2b 5 2c and 2d are formed, whereas in the cam 2b there is formed a pocket 2e. Roller 3 is seated in sleeve 1, in cylindrical part of that roller there is formed a guide 4 as an oblong groove. In the guide 4 there is placed a ball 5. The ball 5 during revolution of the roller 3 against the sleeve 1, depending on the direction of that revolution, is blocked in a pocket 2e formed in the cam 2b or moves freely between cams 2a, 2b, 2c, 2d in positions I 5 II, III, IV marked in fig. 2.
In another form of realization according to the invention, the blocking mechanism consists also of sleeve 1 in which there is seated a roller 3, however cams 2a, 2b, 2c and 2d as well as a pocket 2e in cam 2b are formed in cylindrical part of roller 3, whereas sleeve 1 contains a formed guide 4 as an oblong groove. In the guide 4 there is placed a ball 5. The ball 5 during revolution of the roller 3 against the sleeve 1, depending on the direction of that revolution, is blocked in a pocket 2e formed in the cam 2b or moves between cams 2a, 2b, 2c, 2d in positions I 5 II, III, IV marked in fig. 4.
Blocking mechanism can be embedded into roller blinds construction in two ways. In the first one roller 3 of the blocking mechanism is immovably fixed to roller blinds holder and sleeve 1 is immovably fixed to winding roller of roller blinds, in the second one it is the other way round, what means that sleeve 1 is immovably fixed to roller blinds holder and roller 3 is immovably fixed to winding roller of the roller blinds.
The principle of operation of the invention is identical in both forms of realization. In the rest point of roller blinds, what means entirely wound up sunshade, on winding roller the ball 5 takes position I in guide 4 of roller 3 between cams 2a and 2b, whereas position I allows for rolling of the sunshade. In case of unrolling of the sunshade, wound up on winding roller with at least half-tum if the winding roller, ball 5 moves through position IV into position II between cams 2c and 2d. In this position mechanism allows for unrolling of the sunshade to its desired length, after decelerated unrolling the spring mechanism operates and there is changed direction of revolution of winding roller and rolling of the sunshade. Ball 5 is moved into position III into pocket 2e of cam 2b. In this position of the ball 5 mechanism is blocked and the sunshade at its desired length is stopped. To unlock the mechanism and allow for rolling the sunshade it is needed to slightly pull the sunshade downwards so that winding roller revolves between 1/5 and 1/2 of a turn what makes the ball 5 to move into position I between cams 2a and 2c.
If the blocked sunshade is pulled with more than 1/2 of a turn and next is released, then the ball 5 moves through IV and position II into position III and the sunshade in blocked in a new position.
In another example of realization the blocking mechanism is built from sleeve 1, roller 3 and guide 4 with a ball 5, however on cylindrical part of roller 3 or of sleeve 1 there are formed two pairs of cams 2a, 2b, 2c and 2d, offset one against another with 180°, fig. 5. The principle of operation of the mechanism in this example of realization is analogous to the principles of operation of the variant presented above.