Drive mechanism, particularly for moving and turning the slats of a blind

Claim 2

Drive mechanism, particularly for moving and turning the slats of a blind comprising: (a) a rotatable drive element capable of being rotated in either direction. (b) a first shaft for operating as a screw drive for shifting the slats of a blind along a guide rail. (c) a second reversing shaft for turning slots jointly, (d) means for drivingly connecting said rotatable drive element to said first shaft including a freewheel comprising: (i) a helical groove on said first shaft, (ii) a hollow casing surrounding and spaced from said helical groove and having an axial groove in the interior surface thereof, (iii) a rolling body partially in each said groove, and (iv) means for drivingly connecting said hollow casing and said rotatable drive element, and (e) means for drivingly connecting said rotatable drive element to said second shaft comprising: (i) a drive tube, (ii) a driven casing surrounding said tube, and (iii) means for drivingly coupling said driven casing to said drive tube comprising radially movable blocking elements engaging in one position thereof said drive tube and said casing and in another portion thereof only one of said tube and casing.

Claim 3

Drive mechanism according to claim 1, and means within said driving tube for effecting radial movement of said blocking elements.

Claim 4

Drive mechanism according to claim 2, said last mentioned means comprising a control shaft in said drive tube having axially extending recesses, said control shaft being rotatable between two end positions from a central rest position relative to the drive tube, spring means for urging said control shaft to rest postion, said blocking elements being in said recesses in said other position thereof and engaging full diameter portions of said control shaft in said one position thererof.

Claim 5

Drive mechanism according to claim 3, said casing having inwardly directed and axially extending dogs engaged by said blocking elements in said one position thereof.

Claim 6

Drive mechanism according to claim 4, wherein the blocking elements are constructed as rollers, the longitudinal axes of which are arranged parallel to the axis of the drive tube.

Claim 7

Drive mechanism according to claim 4, wherein the control shaft is provided with a follower spring protruding radially and which is coupled to the screw drive via the freewheel and passes outward through an opening which limits the two end positions of the control shaft with relation to the drive tube.

Claim 8

The mechanism according to claim 6, wherein the follower spring engages an axial groove at the inner surface of a second toothed casing enclosing the drive tube and wherein the second casing meshes with a third toothed casing which is connected to the screw drive via the limited freewheeel.

Claim 9

Drive mechanism according to claim 4, wherein a radial disc firmly rotationally jointed to the control shaft is arranged in an expanded part of the drive tube and has a projection pointing in the axial direction which fits against a projection pointing radially inward from the inner surface of the expanded part of the drive tube and wherein the two ends bent outward of the return spring encircling the control shaft fit laterally in the direction of rotation against the two projections.

Claim 10

Drive mechanism according to claim 7, whererein the return spring is constructed as a helical spring and is arranged in a radial slot between one face each of the expanded part of the drive tube and the radial disc.

Claim 11

Drive mechanism according to claim 1, wherein the rolling body is shaped as a sphere of cylinder and the cross-sections of the two grooves taking the rolling body are fitted to its cross-section.

Claim 12

Drive mechanism according to claim 1, wherein the freewheel shaft is provided with a brake cone against which a brake disc fixed in the direction of rotation is pressed by means of a compression spring.

Claim 13

Drive mechanism according to claim 11, wherein the brake disc is supported to rotate on the freewheel shaft and with a radial protrusion projects into an axial groove of a fixed housing.

Claim 14

Drive mechanism according to claim 12, wherein the compression spring is constructed as a helical spring encircling one end section of the freewheelshaft and the pressure of which against the brake disc can be adjusted by means of a stop plate and a screw inserted into the end of the freewheel shaft.

Claim 15

Drive mechanism, particularly for moving and turning the slats of a blind comprising: (a) rotatable drive element capable of being rotated in either direction. (b) a first shaft for operating as a screw drive for shifting the slats of a blind along a guide rail. (c) a second reversing shaft for turning slats jointly, (d) means for drivingly connecting said rotatable drive element to said first shaft including a freewheel comprising: (i) a tubular basic body fixedly connected to the first shaft, (ii) a hollow casing surrounding at least a portion of said tubular body and rotatable in either direction by said drive element, (iii) radically movable blocking element means for engaging said casing and said body in one position thereof and for engaging only one of said casing and said body in another position thereof to thereby cause conjoint rotational movement of said body by said casing when said blocking element means is in said one position, and (iv) means driven by said hollow casing for moving said blocking element means to said one position after a predetermined amount of rotation of said hollow casing from an initial position, and (e) means for drivingly connecting said rotatable drive element to said second shaft.

Claim 16

Drive mechanism, particularly for moving and turning the slats of a blind comprising: (a) rotatable drive element capable of being rotated in either direction. (b) a first shaft for operating as a screw drive for shifting the slats of a blind along a guide rail. (c) a second reversing shaft for turning slats jointly, (d) means for drivingly connecting said rotatable drive element to said first shaft including a freewheel comprising: (i) a tubular basic body fixedly connected to the first shaft, (ii) a hollow casing surrounding at least a portion of said tubular body and rotatable in either direction by said drive element, (iii) radically movable blocking element means for engaging said casing and said body in one position thereof and for engaging only one of said casing and said body in another position thereof to thereby cause conjoint rotational movement of said body by said casing when said blocking element means is in said one position, and (iv) means driven by said hollow casing for moving said blocking element means to said one position after a predetermined amount of rotation of said hollow casing from an initial position, and (e) means for drivingly connecting said rotatable drive element to said second shaft.

Claim 17

Drive mechanism according to claim 14, wherein said blocking element means comprises an axially extending body, and wherein said tubular basic body has an axial opening therein, said blocking element body being in said opening.

Claim 18

Drive mechanism according to claim 14, wherein said means for moving said blocking element means comprises a blocking shaft within said hollow body having a first axially extending recess therein for permitting said blocking element means to move to said other position.

Claim 19

Drive mechanism according to claim 16, wherein said means for moving said blocking element means further comprises gear means connected with said hollow casing and to said shaft within the hollow body.

Claim 20

Drive mechanism according to claim 17, wherein said basic body has an axial projection and said gear means comprises an internal gear having a recess receiving said axial projection, and an external toothed gear connected to said blocking shaft.

Claim 21

Drive mechanism according to claim 17, said gear means comprising a toothed gear connected to said blocking shaft, means supporting said toothed gear for eccentric motion within said tubular basic body, and a toothed ring fixed to said hollow casing meshing with said toothed gear and having a different number of teeth than said toothed gear.

Claim 22

Drive mechanism according to claim 16, wherein the blocking shaft is made hollow and a pin passes through it axially and is fixed axially to the end of the blocking shaft and to an inner step of the basic body.