AU701631B2

AU701631B2 - An elongated drive member

Info

Publication number: AU701631B2
Application number: AU70296/96A
Authority: AU
Inventors: John Russell Watts
Original assignee: Watts Hardware Manufacturing Pty Ltd
Current assignee: Watts Hardware Manufacturing Pty Ltd
Priority date: 1992-04-10
Filing date: 1996-10-18
Publication date: 1999-02-04
Anticipated expiration: 2013-04-13
Also published as: AU7029696A

Description

P:\OPER\RSH\70296-96.SPE 1/12/98 la- AN ELONGATED DRIVE MEMBER This invention relates to elongated drive members, and more particularly to elongated drive members which are capable of bending when displaced along a predetermined non-linear path, such as may be required in a control device for a pivotally supported window.

Conventionally, window control devices, commonly referred to as window winders, comprise a box-like casing with a chassis housing a winding lever and associated gears which engage a special drive chain housed in the casing and connected to the window leaf The whole assembly is conspicuous high in profile and locates in the middle of the window making it an unpleasant obstruction to viewing through the window. It is also cumbersome to operate i because of the need to turn a relatively small lever numerous times.

0* According to the invention there is provided an elongated drive member having a 15 longitudinal axis, said drive member being capable of bending at multiple positions within its length and having a first end fitting at one end portion and a second end fitting at the opposite end portion, said drive member including an elongated control element in the form of a flexible o but substantially inextendible core within the drive member with respective ends of the control element being attached to the respective end fittings, the drive member when configured for S• 20 movement along a path having at least one non-rectilinear portion being capable of transmitting to the first end fitting an axial displacement substantially the same as that applied axially to the second end fitting, and said control element being operable to restrain the drive member against lateral deflection.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a schematic plan view of a window control device incorporating a drive member in accordance with an embodiment of the invention.

Figure 2 is a schematic view of the inner end of the drive member.

7"r- P:\OPER\RSH\70296-96.SPE 1112/98 -2- Figure 3 is a schematic side view showing elements of one form of drive system associated with the drive member.

Figure 4 is a schematic side view showing another form of drive system associated with the drive member.

Figure 5 is a cross sectional view of one form of the drive member of Figure 1.

Figure 6 is a cross sectional view of another form of the drive member of Figure 1; and Figure 7 is a schematic plan view of portion of an alternative embodiment of the drive member.

In the accompanying drawings and text the reference numerals are used for like components in all embodiments shown. Relative positional descriptions such as rear" and "forward" are used to assist in description of the preferred embodiments but are not intended to ::restrict the scope ofthe invention only to those relative positions.

15 As shown in the drawings, a window control device comprises an elongated drive member 1 supported in a box-like casing 2, the drive member 1 preferably being actuated by a pull cord 3 as shown in Figure 1 or other operating means as discussed later. An outwardly disposed end 6 of the drive member 1 is attached to a window leaf 5, the leaf 5 being moved by 00:: drawing the cord 3 which causes the outer end 6 of drive member I to extend from the casing 2 by a variable distance. The drive member 1 is also used to retain the leaf 5 in the displaced 0position this being achieved by locking of the drive member or actuating means or because of the friction generated when one attempts to operate the device in reverse when the drive member attempts to drive the other portion of the device.

Preferably the drive member 1 is supported within a channel 7 in the casing 2, the channel 7 comprising an elongated portion 7a and a 90 degrees curved portion 9 ending in an outlet aperture 10 through which the outer portion of the drive member 1 leaves the casing 2.

The drive member 1 is capable of bending at multiple positions along its length. Part of the drive member 1 lies within the channel 7 in the casing 2 and conforms to the general shape of the channel, and an outer part of the drive member 1 protruding from the casing 2 projects to P:\OPER\RSH\70296-96.SPE 1/12/98 -3join with movable leaf 5. The protruding part of the drive member 1 has sufficient rigidity to displace and retain the leaf The elongated drive member 1 may be articulated or it may be flexible. In one form, the drive member 1 may be in the form of a tightly wound spring having internally a plastic extrusion with at least one elongated longitudinal peripheral channel within which there is an inextendible cable. There may be two pairs of opposite elongated longitudinal peripheral channels within which there are cables, these cables being retained within the grooves by the adjacent internal wall of the outer spring. In particularly preferred forms as shown in Figures 5 and 6, the drive member comprises an outer solidly wound spring 11 having internally other tightly wound springs 12 to hold at least one cable 13 substantially fixed radially in relation to the longitudinal axis of the outer spring 11. In Figure 5 three inner springs 12 support a single cable 13 on the :i longitudinal axis of the outer spring 11 by together surrounding the cable to prevent radial displacement; alternatively as shown in Figure 6 the three inner longitudinally springs each support internally a cable 13 located longitudinally adjacent the longitudinal axis of the outer spring 11 these cables being substantially restrained against radial displacement.

When the outer spring 11 bends, it does so about a peripheral edge of the outer spring thereby causing the adjacent turns of the opposite edge to part in a fan-like manner thus increasing the longitudinal length of the spring on that side. The inclusion of a substantially inextendible cable within the outer spring 11 longitudinally supported away from the peripheral edge of the outer spring and fixed in relation to each end of the outer spring restrains the outer spring 11 from axially extending to any significant extent and hence bending to any significant extent. If the outer spring 11 is bent to a predetermined extent, such as the single 90 degree bend as normally required in a window winder, and the cable is then fixed in relation to the ends then further significant bending beyond 90 degrees is prevented because the further bending would tend to cause the axial length to increase, and this is prevented by the cable. When the outermost end of the spring 11 is fixed to the leaf 5 and fixed against angular displacement, bending to facilitate lateral deflection similar to buckling is prevented from occurring to any significant extent by the cable.

P:\OPER\RSH\70296-96.SPE 1/12198 -4- At each end of the outer spring 11 there are means for retaining the ends of the cable in relation to the ends of the outer spring 11, such means preferably comprising retaining plates 14 which abut the last coil of the spring 11 and retaining members 15 whereby the cable after passing through an aperture 16 in the plates terminate in and is secured by the retaining members 15 which prevent the ends of the cable being moved in an inward direction towards the plates.

Where there are multiple cables, to accommodate the curved 90 degree bend in the outer spring 11, the cables may be of different length.

When the drive member forms part of a window winder, the plate 14 on the protruding end of the drive member comprises a member 17 securable to the movable window leaf preferably by screws 18 so as to prevent angular displacement of the plate 14 and associated components relative to the window leaf 5, while the retaining plate at the inner end of the drive S:i 5: member 1 within the casing 2 forms part of an extension to a driving slide 19 which is actuable to move the drive member 1.

Preferably the slide 19 is threaded and is supported on an elongated threaded shaft mounted parallel to and adjacent the elongated portion of the channel 7 within the casing 2.

Alternatively, the slide 19 may be supported for longitudinal movement by a wall of the channel 27 and connected to and actuated by at least one looped cable connected to an exterior pull cord.

When the slide 19 is driven by the threaded shaft 20, the slide 19 preferably comprises a threaded portion 21 through which the threaded shaft 20 passes in threaded engagement and a side arm 22 which straddles the side wall of the channel 7 to locate within the channel 7 adjacent the end of the drive member 1, the side arm 22 having a forked extension 24 with forks 27 and 29. The end coil 26 of the drive member 1 abuts the fork 27 while the cable end retainer abuts a washer 28 and is slidable within fork 29, a compression spring 23 under high load being interposed between the fork 27 and washer 28. Such an arrangement allows some axial displacement of the retainer 15 and cable attached thereto against the bias of compression spring 23 under abnormal loading which might otherwise result in breakage of the drive member.

The end of the shaft 20 adjacent the protruding portion of the drive member 1 preferably P:\OPER\RSH\70296-96SPE 1/12/98 is supported by a forked extension 30 of the top wall of the casing, this forming the sides and top of the shaft support while the bottom of the support is formed by a laminar extension from a base cover plate. Preferably, there is a groove 31 in the shaft 20 within which the laminar support locates with clearance to restrain longitudinal movement of the shaft in relation to the casing.

Preferably, the opposite end of the shaft 20 is supported in a similar manner.

Rotation of the shaft 20 in one direction drives the threaded slide 19 to move in one direction to push the drive member 1 to extend from the casing 2 while rotation in the other direction causes the slide 19 to move in the opposite direction to draw the cable 13 and thereby cause the drive member 1 to retract.

The thread pitch on the shaft 20 may vary as is required and is preferably smaller towards :the retracted end of the working range of the thread so that more force may be applied to the window in the last stages of pulling it closed; this smaller thread pitch also serves to increase the S 15 difficulty of driving the shaft by moving the window, in which case the slide thread may comprise a single cylindrical internal protrusion 32.

V The threaded shaft 20 may terminate in a pulley 35 (Figure 4) around which passes a continuous looped cable 33 which passes through an aperture in the lower casing wall 34. Pulling 20 one side of the loop causes the shaft 20 to rotate in one direction while pulling the other side causes it to rotate in the opposite direction.

Preferably the axis 43 of the threaded shaft 20 lies parallel to and at substantially the same height in relation to the casing 2, preferably about 6mm, so that the casing 2 may have a comparatively low profile except possibly in a zone 44 which contains drive means for the shaft In that case the drive end of the shaft and drive means (which may include pulleys or a motor) are interspaced with a height adjusting coupling means 45 (see Figure 3) to accommodate an increased height of drive shaft through the pulleys. In one form the height adjusting coupling means 45 comprises a tightly wound elongated compression spring 46 interconnecting the shaft 20 to a short shaft 20a on which the drive pulleys are mounted as described above, the spring 46 having inwardly projecting arms 47 each end which locate in slots 1_ P:\OPER\RSH\70296-96.SPE 1/12/98 -6- 48 in the drive shafts. The height adjusting coupling means may alternatively comprise conventional gears mounted on the shafts.

In another embodiment the elongated drive member comprises a series of separate, chain articulated, abutting, thrust members as shown in Figure 7 where relative angular displacement in a horizontal plane in one direction is accommodated but prevented in the opposite direction.

The thrust members are similar to the links of a chain but are not pivotally interlinked as in a conventional chain The thrust members preferably comprise substantially spine-like members having at least one aperture 61 adjacent one edge through which a flexible inextendible cord 62, cords or band passes to retain each member to form a bead-like chain; each member 60 has a winged extension 63 which abuts that of the adjacent member when that portion of the chain is straight. If the chain is bent to a predetermined extent such as the single 90 degree bend as ::normally required in a window winder, and the ends are fixed against angular displacement and then any attempt at further significant bending to facilitate lateral deflection similar to buckling S 15 is prevented from occurring to any significant extent by the cord(s) or band.

oooo o In the embodiments described, the internal cable(s) or cord or other elongate element constitutes an internal inextensible core which is linked to the end fittings of the drive member o 2and being substantially inextendible acts to prevent any significant lateral deflection (similar to buckling) of the drive member. As such the effect is similar to that which can be achieved with linked chains designed for the same purpose, but the drive member can be produced at significantly less cost. Also the design of the drive member enables a reduction to be achieved in the depth of the casing containing the drive system.

This application is a divisional application of 37119/93 the disclosure of which is hereby incorporated by reference.

P:\OPER\RSH\70296-96.SPE- 1/12/98 -7- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:- 1. An elongated drive member having a longitudinal axis, said drive member being capable of bending at multiple positions within its length and having a first end fitting at one end portion and a second end fitting at the opposite end portion, said drive member including an elongated control element in the form of a flexible but substantially inextendible core within the drive member with respective ends of the control element being attached to the respective end fittings, the drive member when configured for movement along a path having at least one non-rectilinear portion being capable of transmitting to the first end fitting an axial displacement substantially the same as that applied axially to the second end fitting, and said control element being operable to restrain the drive member against lateral deflection.

*i 2. A drive member according to claim 1, wherein the control element comprises at least one substantially inextendible cable.

3. A drive member according to claim 1, wherein the control element comprises at least one 0 substantially inextendible cord.

0 4. A drive member according to any one of claims 1 to 3, comprising means for maintaining the control element in a substantially predetermined position relative to the longitudinal axis of the drive member.

5. A drive member according to claim 4, wherein the means for retaining the control element in a predetermined position relative to the longitudinal axis of the drive member comprises a plurality of coil springs within the drive member parallel to the longitudinal axis of the drive member.

6. A drive member according to claim 1, wherein the core is formed by a single substantially inextendible element within the drive member and that element is maintained in a predetermined position relative to the longitudinal axis of the drive member by confinement between a plurality Sof coil springs within the drive member and extending parallel to the longitudinal axis of the

Claims

7. A drive member according to claim 1, wherein the core comprises a plurality of substantially inextendible elements and each respective said element is maintained in a predetermined position relative to the longitudinal axis of the drive member by passage through a respective coil spring within the member and extending parallel to the longitudinal axis of the member.
8. A drive member according to any one of the preceding claims, wherein the drive member is formed by a coil spring with abutting coils.
9. A drive member according to claim 1, wherein the drive member comprises a series of separate abutting thrust members supported by the core so that each thrust member is capable of articulation relative to the thrust member adjacent thereto. A control device for a movable wing including an elongated drive member according to any one of the preceding claims, the said first end fitting of the drive member being adapted for attachment to the wing.
11. A control device according to claim 10, wherein the drive member is supported within a casing and said one end portion of the drive member is operative to extend by a variable distance from said casing by displacement of the drive member within the casing to thereby cause corresponding displacement of the wing, said device further comprising actuating means for causing the drive member to displace in relation to the casing.
12. A control device according to claim 11, wherein said actuating means includes a threaded shaft operatively coupled to the drive member.
13. A control device according to claim 12, wherein the actuating means includes at least one pull cord for driving the shaft. P:\OPER\RSH\70296-96.SPE 1/12/98 -9-
14. A control device according to any one of claims 11 to 13, wherein the actuating means includes means for allowing restricted longitudinal displacement between the other end portion of the drive member and the adjacent end of the core to obviate breakage in the event that an abnormal force is applied to the control device. A control device according to any one of claims 10 to 14 in the form of a window winder, wherein the movable wing is a pivotal window leaf to which the said one end fitting is attached.
16. A control device substantially as hereinbefore described with reference to the accompanying drawings.
17. An elongated drive member substantially as hereinbefore described with reference to the accompanying drawings. DATED this 1st day of December, 1998 JOHN RUSSELL WATTS By his Patent Attorneys: DAVIES COLLISON CAVE S* *o o* P:\OPER\RSH\37119.DrV 18/10/96 ABSTRACT *9 a a a a a a a. An elongated drive member which is bendable at multiple positions within its length yet resistant to buckling by means to resist longitudinal lengthening.