GB2145786A - Blind winding drum - Google Patents

Abstract

A blind winding drum comprising a lever operated clutch mounted in a casing (13) having a cover (16). The clutch comprises a disc (2) having a shaft (3) with a decreasing stepped diameter, on the outer end of which the operating lever (5) is mounted. The face of the disc from which the shaft (3) protrudes has an annular collar (6) with an open sector (7) in which a pawl (8) is floatingly disposed, the pawl (8) being housed between an externally toothed gear ring (9) and disposed on the outer zone of the annular collar (6). A circular flange (10) is placed on one of the faces of the reel (12) between the annular collar (6) and the shaft (3) of the disc (2), the entire assembly fitting into a cylindrical housing (1) inside the casing (13), which housing incorporates a rachet (14) for blocking the toothed gear ring (9) in one direction and for allowing its free turning in the opposite direction. <IMAGE>

Description

SPECIFICATION Blind winding drum The present invention refers to a winding drum for a blind.

Generally the object of this invention comprises a handle or crank actuated clutch installed in a housing.

The clutch is specifically comprised of a disc with its corresponding shaft having a decreasing stepped diameter to be fixed to the free end of the actuating lever, one face of which disc has an annular collar with an open portion in which a pawl is floatingly disposed.

The outer zone of the collar is provided with a ring gear having a toothed outer contour, while a circular flange disposed at one of the faces of the reel of cord is provided in the channel formed by the annular collar and its shaft. Said circular flange of the reel is provided with a small radial projection placed in the open portion of the annular collar of the disc, which is capable of contacting the floating pawl or one of the ends of the open annular collar. The toothed ring gear is in contact with a ratched fixed to the mechanism housing.

One embodiment of the object consists in replacing the mentioned ratchet by a draw-in bolt which does not alter the structure of the invention and only and exclusively constitutes one of the various embodiments which can be derived from the structure of the blind winding drum of the present invention.

To complete the description to be made and for a better understanding of the characteristics of the invention, a set of drawings is accompanied wherein: Figure 1 corresponds to a perspective view of the entire assembly of the winding drum, broken away.

Figure 2 corresponds to a perspective view of the winding drum incorporating all its elements, broken away to illustrate all the elements of which it is comprised.

As can be seen from the mentioned figures, the blind winding drum of the present invention is comprised of a clutch incorporated in a mechanism housing 1, comprising a disc 2 provided at one of its faces with a protruding shaft 3 having a decreasing stepped diameter, terminating in a hexagonal stud 4 acting as the coupling element to the end of the actuating lever 5.

The disc 2, on the same face from which the shaft 3 protrudes, has an annular collar 6 provided with an open sector 7. A floating pawl 8 fits in the open sector 7 and an externally toothed gear ring 9 fits to the outer surface of the collar.

A circular flange 10 provided radially with a projection 11 fits in the channel formed by the collar 6 and the shaft 3, the flange 10 and the projection 11 being disposed on one of the faces of the reel 12, in such a way that the projection 11 is housed in the open sector 7 and is in contact with one of the ends of the collar 6 and with the floating pawl 8.

The entire clutch assembly incorporated in the housing 1 is mounted in a casing 13. The casing 13 and the housing 1 are provided with a ratchet 14 and its corresponding anchor plunger, which ratchet acts on the gear ring 9, blocking its movement in one direction whilst permitting its free turn in the other.

The clutch assembly is mounted at its ends by washers 15 to the bottom of the casing 13 and to the cover 16 covering the casing 13.

The cover 16 is protected by an ornamental head cover 17, both the cover and the head cover being provided with the corresponding hole for the passage of the hexagonal stud 6 for coupling to the lever 5, which stud 4 is protected by the handle plug 18.

The cord 19 is fixed at one of its ends to the reel 12 on which it will be wound or unwound.

With this constitution, functioning of the blind winding drum is as follows: On activating the lever 5 and the shaft 3 of the clutch disc 2, when pulling up the blind, the mentioned disc 2 pulls the reel 12, since its projection 11 fits in one end of the annular collar 6 of the disc 2, freeing the floating pawl 8, the gear ring 9 thereby being retained by its ratchet 14.

When the blind is no longer pulled, there is a slight return of the clutch, motivated by the weight of the blind, causing the projection 11 to press the pawl 8 against the gear ring 9 retained by the ratchet 14, wherefore the assembly is locked.

On activating the lever 5 in the opposite direction to lower the blind, the entire assembly turns, whilst the ratchet 14 freely passes the teeth of the gear ring 9 until the descending movement is stopped, at which moment the ratchet 14 acts again on the ring gear 9, locking any undesired turn.

The clutch can operate in both turning directions at will, by merely changing the position of the elements.

Another embodiment resides in that instead of the ratchet 14 in the form of a pawal to retain the toothed gear ring 9 in one direction of turn, a draw-in bolt is placed in the same location as the mentioned ratchet.

Likewise, the lever 5 can be operated directly from the shaft or the mentioned lever 5 can be operated from a reducing toothed wheel which meshes with the clutch disc 2, that is with the toothed periphery of the disc 2.

1. Blind winding drum comprised of a lever operated clutch mounted in a prismatic casing having a cover, characterised in that the clutch is comprised of a disc having a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Blind winding drum The present invention refers to a winding drum for a blind. Generally the object of this invention comprises a handle or crank actuated clutch installed in a housing. The clutch is specifically comprised of a disc with its corresponding shaft having a decreasing stepped diameter to be fixed to the free end of the actuating lever, one face of which disc has an annular collar with an open portion in which a pawl is floatingly disposed. The outer zone of the collar is provided with a ring gear having a toothed outer contour, while a circular flange disposed at one of the faces of the reel of cord is provided in the channel formed by the annular collar and its shaft. Said circular flange of the reel is provided with a small radial projection placed in the open portion of the annular collar of the disc, which is capable of contacting the floating pawl or one of the ends of the open annular collar. The toothed ring gear is in contact with a ratched fixed to the mechanism housing. One embodiment of the object consists in replacing the mentioned ratchet by a draw-in bolt which does not alter the structure of the invention and only and exclusively constitutes one of the various embodiments which can be derived from the structure of the blind winding drum of the present invention. To complete the description to be made and for a better understanding of the characteristics of the invention, a set of drawings is accompanied wherein: Figure 1 corresponds to a perspective view of the entire assembly of the winding drum, broken away. Figure 2 corresponds to a perspective view of the winding drum incorporating all its elements, broken away to illustrate all the elements of which it is comprised. As can be seen from the mentioned figures, the blind winding drum of the present invention is comprised of a clutch incorporated in a mechanism housing 1, comprising a disc 2 provided at one of its faces with a protruding shaft 3 having a decreasing stepped diameter, terminating in a hexagonal stud 4 acting as the coupling element to the end of the actuating lever 5. The disc 2, on the same face from which the shaft 3 protrudes, has an annular collar 6 provided with an open sector 7. A floating pawl 8 fits in the open sector 7 and an externally toothed gear ring 9 fits to the outer surface of the collar. A circular flange 10 provided radially with a projection 11 fits in the channel formed by the collar 6 and the shaft 3, the flange 10 and the projection 11 being disposed on one of the faces of the reel 12, in such a way that the projection 11 is housed in the open sector 7 and is in contact with one of the ends of the collar 6 and with the floating pawl 8. The entire clutch assembly incorporated in the housing 1 is mounted in a casing 13. The casing 13 and the housing 1 are provided with a ratchet 14 and its corresponding anchor plunger, which ratchet acts on the gear ring 9, blocking its movement in one direction whilst permitting its free turn in the other. The clutch assembly is mounted at its ends by washers 15 to the bottom of the casing 13 and to the cover 16 covering the casing 13. The cover 16 is protected by an ornamental head cover 17, both the cover and the head cover being provided with the corresponding hole for the passage of the hexagonal stud 6 for coupling to the lever 5, which stud 4 is protected by the handle plug 18. The cord 19 is fixed at one of its ends to the reel 12 on which it will be wound or unwound. With this constitution, functioning of the blind winding drum is as follows: On activating the lever 5 and the shaft 3 of the clutch disc 2, when pulling up the blind, the mentioned disc 2 pulls the reel 12, since its projection 11 fits in one end of the annular collar 6 of the disc 2, freeing the floating pawl 8, the gear ring 9 thereby being retained by its ratchet 14. When the blind is no longer pulled, there is a slight return of the clutch, motivated by the weight of the blind, causing the projection 11 to press the pawl 8 against the gear ring 9 retained by the ratchet 14, wherefore the assembly is locked. On activating the lever 5 in the opposite direction to lower the blind, the entire assembly turns, whilst the ratchet 14 freely passes the teeth of the gear ring 9 until the descending movement is stopped, at which moment the ratchet 14 acts again on the ring gear 9, locking any undesired turn. The clutch can operate in both turning directions at will, by merely changing the position of the elements. Another embodiment resides in that instead of the ratchet 14 in the form of a pawal to retain the toothed gear ring 9 in one direction of turn, a draw-in bolt is placed in the same location as the mentioned ratchet. Likewise, the lever 5 can be operated directly from the shaft or the mentioned lever 5 can be operated from a reducing toothed wheel which meshes with the clutch disc 2, that is with the toothed periphery of the disc 2. CLAIMS

1. Blind winding drum comprised of a lever operated clutch mounted in a prismatic casing having a cover, characterised in that the clutch is comprised of a disc having a shaft with a decreasing stepped diameter, to the outer end of which the operating lever fits, the face of the disc from which the shaft protrudes has an annular collar with an open sector in which a pawal is disposed floatingly, which pawl is housed between an externally toothed gear ring and disposed on the outer zone of the annular collar, and a circular flange placed on one of the faces of the reel between the annular collar and the s shaft of the disc, the entire assembly fitting into a cylindrical housing inside a casing, which housing incorporates means for blocking the toothed gear ring in one direction and for allowing its free turn in the opposite direction.

2. Blind winding drum according to claim 1, characterised in that the means for blocking the toothed gear ring in one direction comprises a ratchet incorporated in a shaft placed inside a prolongation of the cylindrical housing.

3. Blind winding drum according to claim 1, characterised in that the means for blocking the toothed gear ring in a single direction comprises a draw-in bolt placed in the cylindrical housing.

4. A blind winding drum substantially as described with reference to, and as illustrated in, the accompanying drawings.