AU2016256792B2

AU2016256792B2 - A window balance

Info

Publication number: AU2016256792B2
Application number: AU2016256792A
Authority: AU
Inventors: Michael Brian Alchin
Original assignee: Azuma Design Pty Ltd
Current assignee: Azuma Design Pty Ltd
Priority date: 2015-12-01
Filing date: 2016-11-11
Publication date: 2022-09-01
Anticipated expiration: 2036-11-11
Also published as: AU2016256792A1

Abstract

A WINDOW BALANCE ABSTRACT A window balance mechanism (10) that includes a helical spring (11) having a lower end attached to the window sash. The spring (11) is located in a tube (19) that is formed of plastics material, with a friction member (22) slidably engaged with the tube (19) and also attached to the sash so as to provide a frictional force that is in combination with the spring (11) aids in retaining the sash window stationary in a desired position. 1/3 2929 22- 20 24 1 1 1 7 1 1-73

Description

1/3

2929

22- 20

24

1 1 1 7 1 1-73

A WINDOW BALANCE FIELD

[0001] The present invention relates to balance mechanisms for sash windows, and more particularly but not exclusively to balance mechanisms for sash windows that are at least partly formed of aluminium extrusions.

BACKGROUND

[0002] Traditionally sash windows were of a timber construction, with the balance mechanism merely being a counterweight.

[0003] With the increase in use of extruded aluminium sections in the construction of sash windows, the balance mechanisms were replaced with springs and break mechanisms.

[0004] More recently, balance mechanisms have included a spring that extends between the frame and the sash, with a break extending between the frame and sash. Cooperation of the spring tension, and the break mechanism retains the sash at a desired location relative to the frame.

[0005] The above balance mechanisms have a number of disadvantages, including not always retaining the sash stationary. Typically, in respect of aluminium windows, surface finishes on the frame and/or sash influenced the break mechanism, resulting in the mechanism being unreliable.

OBJECT

[0006] It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.

SUMMARY

[0007] There is disclosed herein a window balance mechanism to be attached to a window frame and a sash slidable supported by the frame for generally vertical movement relative to the frame, the mechanism including: a spring having an upper end attached to be attached to the frame, and a lower end to be attached to the sash so that downward movement of the sash relative to the frame tensions the spring; a first friction member, the first friction member being longitudinally elongated and attached to the frame so as to be longitudinally upwardly oriented; a second friction member, the second friction member being frictionally engaged with the first member and movable longitudinally of the first member, the second member being adapted to be attached to the sash to move with the sash; and wherein tensioning of the spring and frictional engagement between the first and second members at least aids in retaining the sash in a desired position relative to the frame, wherein the first member is an elongated tube, with the spring located in the tube; wherein the second member has a tube engaging portion, with an aperture within which the tube is received, and that frictionally engages the tube; and wherein the tube engaging portion is a first portion, and the second member includes a second tube engaging portion, the second portion having an aperture within which the tube is received so that the second portion frictionally engages the tube, the first portion being spaced from the second portion longitudinally of the tube.

[0008] Preferably, the mechanism includes a frame engaging bracket, attached to an upper portion of the tube and attaching the upper portion of the spring to the tube, and being adapted to be attached to the frame to thereby attach the spring to the frame.

[0009] Preferably, a threaded fastener passes through an upper portion of the tube to secure the tube to the frame.

[0010] Preferably, the mechanism further includes a bracket mounted on an end portion of the tube, and to which the spring is attached so that the spring is tensioned.

[0011] Preferably, the tube is formed of plastics material.

[0012] Preferably, the tube is of a cylindrical configuration.

[0013] Preferably, the tube is an extrusion plastics material.

[0014] Preferably, the second member is formed of plastics material.

[0015] Preferably, the second member is moulded.

[0016] Preferably, the mechanism includes a sash engaging bracket, attached to the lower end of the spring, and that is to be attached to the sash.

[0017] Preferably, the sash bracket is adapted to snap engage with a portion of the frame.

[0018] Preferably, the first member further includes an elongated portion connecting the first and second portions, and a laterally extending flange that is to be fixed to the sash.

BRIEF DESCRIPTION OF DRAWINGS

[0019] Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings wherein:

[0020] Figure 1 is a schematic side elevation of a window balance mechanism;

[0021] Figure 2 is a schematic front elevation of the balance mechanism of Figure 1;

[0022] Figure 3 is a schematic rear elevation of the balance mechanism of Figure 1;

[0023] Figure 4 is a schematic top plan view of the balance mechanism of Figure 1;

[0024] Figure 5 is a schematic bottom plan view of the balance mechanism of Figure 1;

[0025] Figure 6 is a schematic isometric view of a sash engaging bracket of the mechanism of Figure 1;

[0026] - [0028] are intentionally left blank.

[0029] Figure 7 is a schematic top plan view of the bracket of Figure 6;

[0030] Figure 8 is a schematic side elevation of the bracket of Figure 6;'

[0031] Figure 9 is a further schematic side elevation of the bracket of Figure 6;

[0032] Figure 10 is a schematic isometric view of a friction member of the mechanism of Figure 1;

[0033] Figure 11 is a schematic side elevation of the member of Figure 10;

[0034] Figure 12 is a schematic front elevation of the member of Figure 10;

[0035] Figure 13 is a schematic bottom plan view of the member of Figure 10; and

[0036] Figure 14 is a schematic top plan view of the member of Figure 10.

DESCRIPTION OF EMBODIMENTS

[0037] In the accompanying drawings there is schematically depicted a window balance mechanism 10 for a sash window. In one preferred form, the mechanism 10 is adapted to be attached to a sash window in which at least part of the window frame is formed of aluminium extrusion, and at least part of the sash is also formed of aluminium extrusion.

[0038] The mechanism10 includes an elongated helical spring 11that has a lower end in a form of an eyelet or hook 12 that is attached to the sash.

[0039] Preferably, the eyelet 12 is attached to a horizontal member of the sash by means of a sash engaging bracket 13.

[0040] The bracket 13 has a base 14 providing a pair of resiliently deformable arms that snap engage within a horizontal member of the sash, so as to be secured thereto. Extending upwardly from the base 14 is a post 16 having a hook 17 passing through the eyelet 12 to secure the lower end of the spring 11 to the bracket 13, and therefore the sash.

[0041] Attached to a vertical member of the frame is a first friction member 18. The friction member 18 is upwardly elongated and is to be attached to the frame so as to be generally parallel to a vertical member of the frame.

[0042] In this embodiment the member 18 is a tube 19 that is formed of plastics material, and most preferably is an extrusion. In a particularly preferred form, the tube 19 is cylindrical so as to have an outer surface that is circular in transverse cross-section. The tube 19 has a longitudinal axis 21 that is generally vertically oriented.

[0043] Slidably but frictionally engaged with the surface 20 is a second friction member 22. In this embodiment the member 22 has an elongated base 23 that is generally vertically oriented, from which there laterally extends a pair of friction portions 24 slidably engaged with the surface 20.

[0044] The portions 24 each have an internal surface 25 that is part of a cylinder and that engages the tube 19, and is therefore of a shape corresponding to the tube 19. The member 22 is preferably moulded of plastics material so that the portions 24 snap engage over the tube 19. In particular, the parts 24 include a pair of resilient arms 25 that are resiliently moved apart to provide for location of the tube 19 in the apertures 27 provided by the parts 24.

[0045] Extending laterally from the base 23 is an attachment flange 28 that is fixed to the sash. Preferably, the flange 28 would be configured to engage internally with an upwardly extending sash member.

[0046] Fixed to an upper portion of the tube 19 is a frame engaging bracket in the form of a cap 29. The cap 29 has a downwardly extending hook (not shown) to which the upper end of the spring 11 is attached. The upper end of the spring 11 would be provided with an eyelet but will engage the hook of the cap 29.

[0047] Extending laterally through an upper portion of the tube 19 and past the cap 29 is a threaded fastener 30. The threaded fastener 30 engages a vertical member of the frame adjacent the tube 19, to fix the tube 19 thereto.

[0048] When the tube 19 is engaged with the surfaces 25, the arms 26 are resiliently deformed so as to be urged into contact with the surface 20. Accordingly, there is frictional force created between the engagement of the surface 20 and the surfaces 25.

[0049] In operation of the above described balance mechanism 10, cooperation between tension in the spring 11, and the friction forces between the friction member 22 and the tube 19 retain the sash at a desired location relative to the surrounding frame. In this respect it should be appreciated the spring 11 is always tensioned. That is, as the sash is lowered, the tension increases.

Claims

CLAIMS:

1. A window balance mechanism to be attached to a window frame and a sash slidable supported by the frame for generally vertical movement relative to the frame, the mechanism including: a spring having an upper end attached to be attached to the frame, and a lower end to be attached to the sash so that downward movement of the sash relative to the frame tensions the spring; a first friction member, the first friction member being longitudinally elongated and attached to the frame so as to be longitudinally upwardly oriented; a second friction member, the second friction member being frictionally engaged with the first member and movable longitudinally of the first member, the second member being adapted to be attached to the sash to move with the sash; and wherein tensioning of the spring and frictional engagement between the first and second members at least aids in retaining the sash in a desired position relative to the frame, wherein the first member is an elongated tube, with the spring located in the tube; wherein the second member has a tube engaging portion, with an aperture within which the tube is received, and that frictionally engages the tube; and wherein the tube engaging portion is a first portion, and the second member includes a second tube engaging portion, the second portion having an aperture within which the tube is received so that the second portion frictionally engages the tube, the first portion being spaced from the second portion longitudinally of the tube.

2. The window balance mechanism of claim 1, further including the mechanism includes a frame engaging bracket, attached to an upper portion of the tube and attaching the upper portion of the spring to the tube, and being adapted to be attached to the frame to thereby attach the spring to the frame.

3. The window balance mechanism of claim 1 or 2, wherein a threaded fastener passes through an upper portion of the tube to secure the tube to the frame.

4. The window balance mechanism of claim 1, 2 or 3, wherein the mechanism further includes a bracket mounted on an end portion of the tube, and to which the spring is attached so that the spring is tensioned.

5. The window balance mechanism of any one of claims 1 to 4, wherein the tube is formed of plastics material.

6. The window balance mechanism of any one of claims I to 5, wherein the tube is of a cylindrical configuration.

7. The window balance mechanism of any one of claims I to 6, wherein the tube is an extrusion plastics material.

8. The window balance mechanism of any one of claims I to 7, wherein the second member is formed of plastics material.

9. The window balance mechanism of claim 8, wherein the second member is moulded.

10. The window balance mechanism of any one of claims 1 to 9, wherein the mechanism includes a sash engaging bracket, attached to the lower end of the spring, and that is to be attached to the sash.

11. The window balance mechanism of claim 10, wherein the sash bracket is adapted to snap engage with a portion of the sash.

12. The window balance mechanism of any one of claims 1 to 11, wherein the first member further includes an elongated portion connecting the first and second portions, and a laterally extending flange that is to be fixed to the sash.

13. The window balance mechanism of any one of claims I to 12, wherein the first tube engaging portion is adapted to be attached to the sash at a top end thereof, and wherein the second tube engage portion is longitudinally spaced from the first engaging portion toward a bottom portion of the sash.

14. The window balance mechanism of any one of claims I to 13, wherein the second friction member includes an attachment flange configured to engage internally with an upwardly extending sash member.

15. The window balance mechanism of any one of claims I to 14, wherein the spring is to be attached to the sash at a lower portion thereof, and the second friction member is adapted to be attached to the sash at a top portion thereof.

Azuma Design Pty Limited Patent Attorneys for the Applicant/Nominated Person GLMR