Push-pull chain actuator

Abstract

A push-pull chain type window actuator with an elongated and slim housing. The actuator is slim enough for mounting inside a window frame. The housing includes a chain path in communication with a chain exit. The push pull chain is engaged by a sprocket that is driven via a transmission by two or more electric drive motors in tandem. An auxiliary axial bearing supports the drive shafts of the electric drive motors. The transmission includes a worm gear. In order to extend the life span of the wormwheel the thickness of the teeth of the metal worm is chosen to be significantly less than the thickness of the plastic wormwheel. A resilient stop block dampens the halt of the push-pull chain at the end of the outward stroke.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present description, the invention will be explained in more detail with reference to the exemplary embodiments shown in the drawings, in which

FIG. 1 is a perspective cut-away view on a push-pull chain type window actuator according to an embodiment of the invention,

FIG. 2 is an elevated view on a push-pull chain type window actuator according to FIG. 1,

FIG. 2 a is a detailed cutaway view on a part of the housing and housing elements of the window actuator according to FIG. 1,

FIG. 3 is a cutaway view on the motor and transmission part of the actuator according to FIG. 1,

FIG. 4 is a detailed view on the axial bearing of the push-pull chain type window actuator according to of FIG. 1,

FIG. 5 is a detailed view on the transmission of the push-pull chain type window actuator according to of FIG. 1,

FIG. 6 is a detailed cutaway view on the gearwheels of the transmission of the actuator according to FIG. 1,

FIG. 7 is a detailed elevated cross-sectional view on the transmission of the actuator according to FIG. 1,

FIG. 8 is a detailed cross-sectional side view on the transmission of the actuator according to FIG. 1,

FIG. 9 a to 9d are top-, side-detailed cross-sectional and detailed elevated views of the a worm and wormwheel and their tooth profile according to an embodiment of the invention.

Claims

1. A push-pull chain type window actuator for mounting inside or on a window frame comprising: a sprocket,an elongated and slim actuator housing provided with a chain path in communication with a chain exit opening,a push-pull chain being at least partially received in the chain path and being engaged by the sprocket, andan electric drive motor with a drive shaft coupled to the sprocket via a transmission,characterized by comprising at least one further electric drive motor with a drive shaft coupled to rotate in unison with the drive shaft of said electric motor.

2. A push-pull chain actuator according to claim 1, wherein the axis of the drive shaft of said electric drive motor is arranged substantially in parallel with the longitudinal axis of said housing.

3. A push-pull chain actuator according to claim 1, wherein the axis of the drive shaft of said electric drive motor and the axis of the drive shaft of said at least one further electric drive motor substantially coincide.

4. A push-pull chain actuator according to claim 3, wherein the opposite ends of the drive shaft of said electric drive motor protrude from the opposite sides of the housing of said electric drive motor, whereby the drive shaft of said at least one further electric drive motor is coupled to one of said opposite ends whilst said transmission is coupled to the other one of said opposite ends.

5. A push-pull chain actuator according to claim 3, wherein said drive shaft of said electric drive motor and the axis of the drive shaft of said at least one further electric drive are substantially rigidly connected to one another.

6. A push-pull chain actuator according to claim 5, wherein said drive shaft of said electric drive motor and the axis of the drive shaft of said at least one further electric drive are connected to one another by a connecting shaft with hollow ends in which the respective drive shafts are received.

7. A push-pull chain actuator according to any of claim 1, wherein said transmission comprises wormwheel and a worm, the worm being driven by one of said drive shafts.

8. A push-pull chain actuator according to claim 7, herein said worm is mounted on an end of the drive shaft of said electric drive motor.

9. A push-pull chain actuator according to claim 8, wherein the other end of the drive shaft of said electric drive motor is coupled to the end of the drive shaft of said further electric drive motor by a direct mechanical connection.

10. A push-pull chain actuator according to any of claims 1, wherein said electric drive motor and said further electric drive motor have substantially cylindrical housings with equal diameters.

11. A push-pull chain actuator according to claim 10, wherein the elongated housing has a substantially cuboid shape, and whereby at least one of the two traverse dimensions of the housing is substantially equal to the diameter of the housing of said electric drive motor and said further electric motor.

12. A push-pull chain actuator according to any of claims 1, further comprising a supplementary axial bearing supporting one or both of said drive shafts, preferably an axial bearing that engages said connecting shaft.

13. A push-pull chain actuator according to claim 12, wherein the supplementary axial bearing is resiliently suspended from the housing.

14. A push-pull chain type window actuator for mounting inside or on a window frame comprising: an elongated and slim actuator housing provided with a chain path in communication with a chain exit opening,a push-pull chain being at least partially received in the chain path and operably coupled to a drive mechanism including a worm and wormwheel,an electric drive motor, said wormwheel being mounted on the drive shaft of said electric drive motor,characterized by a supplementary axial bearing supporting said drive shaft.

15. A push-pull chain actuator according to claim 14, wherein said supplementary axial bearing is at least in an axial direction resiliently suspended from said housing.

16. A push-pull chain actuator according to claim 14, wherein said supplementary axial bearing is rigidly connected to a traverse plate member.

17. A push-pull chain actuator according to claim 16, wherein said plate member is sandwiched between two resilient plate members.

18. A push-pull chain actuator according to claim 17, wherein said plate member and said resilient plate member fit tightly in a recess in said elongated slim housing.

19. A push-pull chain actuator according to claim 17, wherein said plate member and said resilient plate members have a substantially circular contour.

20. A push-pull chain actuator according to any of claims 14, wherein said axial bearing is a deep groove roller bearing, preferably a single row deep groove ball bearing.

21. A push-pull chain actuator according to any of claims 14, wherein said electric drive motors are equipped with slide bearings, preferably slide bearings with a plastic or PTFE bearing surface in collaboration with a steel drive shaft.

22. A push-pull chain type window actuator for mounting inside or on a window frame comprising: an elongated and slim actuator housing provided with a chain path in communication with a chain exit opening,a push-pull chain being at least partially received in the chain path and being operably coupled to a drive mechanism including a metal worm meshing with a non-metallic wormwheel,an electric drive motor, said worm being mounted on the drive shaft of said electric drive motor,characterized in that,the tooth thickness of the teeth of the worm is substantially smaller than the tooth thickness of the teeth of the wormwheel.

23. A push-pull chain actuator according to claim 22, wherein the profile angle—the angle between a tangent to a tooth profile and the radius from the gear axis to the tangent point—of the worm and the wormwheel is substantially less than 20°, preferably between 8 and 16°.

24. A push-pull chain actuator according to claim 22, wherein the worm is formed of carbon steel and the wormwheel is made of a plastic resin.

25. A push-pull chain actuator according to claim 22, wherein the tooth thickness of the teeth of the worm are equal to or less than half of the tooth thickness of the wormwheel.

26. A push-pull chain type window actuator comprising: a sprocketan elongated and slim actuator housing provided with a chain path in communication with a chain exit opening,a push-pull chain being at least partially received in the chain path and being operably coupled to a drive mechanism including a metal worm meshing with a non-metallic wormwheel,an electric drive motor, said worm being mounted on the drive shaft of said electric drive motor,a spur gear with at least two stages, with a first gear wheel meshing with a second gearwheel to form the first stage and the second gear wheel meshing with a third gearwheel to form the second stage,characterized in that,the second gearwheel has a given width at its meshing edge,said first gearwheel meshes with said second gearwheel in a first contact length that is less than the width of said meshing edge and the first contact length extends along said width starting from a first side of said second gearwheel towards the second opposite side of said second gearwheel,said third gearwheel meshes with said second gearwheel in a second contact length that is less than the width of said meshing edge, and the second contact length extends along said width starting from said second side of the second gearwheel towards the first side of the second gearwheel.

27. A push-pull chain type window actuator according to claim 26, wherein the third gearwheel is axially displaced relative to the first gearwheel.

28. A push-pull chain type window actuator according to claim 27, wherein said first-, second-, and third gearwheels are each mounted on a shaft, the ends of each of said shafts being received in recesses in oppositely disposed walls of a housing.

29. A push-pull chain type window actuator according to claim 28, wherein said first gearwheel is a relatively small diameter gearwheel in which and the second- and third gearwheels are relatively large diameter gearwheels provided with a countersink in a side of the gearwheel adjacent a housing wall.

30. A push-pull chain type window actuator comprising: a sprocket,an elongated and slim actuator housing provided with a chain path in communication with a chain exit opening,a push-pull chain being at least partially received in the chain path and being engaged by the sprocket,an electric drive motor with a drive shaft coupled to the sprocket via a transmission, andsaid push pull chain having a distal end of connection to a window sash to be actuated and a proximate end pivotally attached to the actuator housing,the final link at the proximate end of the push pull chain swinging from a first orientation to another orientation during the final part of the outward movement of the push-pull and abuts with a resilient rubber stop block disposed in the actuator housing to thereby dampen the halt of the push pull chain at the end of its outward stroke.

31. A push-pull chain actuator according to claim 30, wherein the actuator housing includes a chain attachment block provided with a bore for receiving a pin of the final link of the push-pull chain and the resilient stop block being fitted in a recess formed in said chain attachment block.