Spiral balance device

Abstract

A spiral balance device for sash windows has a pipe inside of which extends a spiral rod having a screw section. A lower end of the spiral rod extends through a slot in a coupling rotatably disposed inside the lower end of the pipe and projects from the lower end of the pipe. A torsion spring has an upper end fixed near the upper end of the pipe and a lower end fixed to the coupling. A fixing member is fixed within the upper end of the pipe, and an adjustment member rotatably disposed below the fixing member engages with the upper end of the spiral rod. A ratchet mechanism disposed between the fixing member and adjustment member allows rotation of the adjustment member in a direction of winding the torsion spring and prevents rotation of the adjustment member in a direction of unwinding the torsion spring.

Claims

1. A spiral balance device, comprising: a pipe having an upper end and a lower end; a spiral rod having a first terminal housed in the pipe, a second terminal which projects from the lower end of the pipe, and a screw section extending in an axial direction between the first and second terminals; a coupling rotatably disposed near the lower end of the pipe and having a slot through which extends the spiral rod; a torsion spring having a lower end fixed to the coupling to rotate therewith and an upper end fixed near the upper end of the pipe; a fixing member fixed within the upper end of the pipe; an adjustment member rotatably disposed in the pipe below the fixing member and having an engagement projection engageable with the first terminal of the spiral rod; and a ratchet mechanism disposed between the fixing member and the adjustment member and which, relative to the fixing member, allows the adjustment member to rotate in a direction of winding the torsion spring and prevents the adjustment member from rotating in a direction of unwinding the torsion spring.

2. The spiral balance device according to claim 1; wherein the ratchet mechanism has ratchet teeth disposed on the lower face of the fixing member and the upper face of the adjustment member, each ratchet tooth having a slant face slanting in a circumferential direction of the pipe and a stepped portion positioned at one end of the slant face.

3. The spiral balance device according to claim 1; wherein the adjustment member has a projection extending through an axial hole at the center of the fixing member, and a stopper spring disposed around the projection for urging the adjustment member toward the fixing member side.

4. The spiral balance device according to claim 3; wherein the stopper spring is disposed between an enlarged-head section at the front end of the projection and an upper face of the fixing member.

5. A spiral balance device, comprising: a pipe having an upper end and a lower end; a spiral rod extending axially inside the pipe and having an upper end portion disposed in the pipe, a lower end portion projecting from the lower end of the pipe, and a screw section extending axially between the upper and lower end portions; a coupling rotatably disposed inside the pipe near the lower end thereof and having a slot through which extends the screw section; a torsion spring extending axially inside the pipe and having a lower end fixed to the coupling to rotate therewith and an upper end fixed near the upper end of the pipe; a fixing member fixed within an upper end portion of the pipe; an adjustment member rotatably disposed in the pipe below the fixing member and engageable with the upper end portion of the spiral rod so that rotation of the spiral rod effects rotation of the adjustment member; and a ratchet mechanism disposed between the fixing member and the adjustment member and which, relative to the fixing member, allows the adjustment member to rotate in a direction of winding the torsion spring and prevents the adjustment member from rotating in a direction of unwinding the torsion spring.

6. The spiral balance device according to claim 5; wherein the ratchet mechanism comprises ratchet teeth on the adjustment member in sliding engagement with ratchet teeth on the fixing member.

7. The spiral balance device according to claim 6; wherein each ratchet tooth has a slant face slanting in a circumferential direction of the pipe and a stepped portion at one end of the slant face.

8. The spiral balance device according to claim 7; including a stopper spring that biases the ratchet teeth of the adjustment member into engagement with the ratchet teeth of the fixing member so that rotation of the adjustment member in the direction of winding the torsion spring causes the slant faces of the adjustment member ratchet teeth to slide along the slant faces of the fixing member ratchet teeth to move the adjustment member downwardly against the bias of the stopper spring, and when the stepped portions of the adjustment member ratchet teeth slide over the stepped portions of the fixing member ratchet teeth, the adjustment member is biased upwardly by the stopper spring causing the slant faces of the adjustment member ratchet teeth to rapidly abut the slant faces of the fixing member ratchet teeth and generate an audible abutment sound.

9. The spiral balance device according to claim 8; wherein the adjustment member has a projection that extends upwardly through an opening at the center of the fixing member, the stopper spring being disposed around the projection.

10. The spiral balance device according to claim 9; wherein the projection has an enlarged-head section, and the stopper spring is interposed between the enlarged-head section and the fixing member.

11. The spiral balance device according to claim 6; including a stopper spring interposed between the adjustment member and the fixing member for biasing the ratchet teeth of the adjustment member into engagement with the ratchet teeth of the fixing member.

12. The spiral balance device according to claim 11; wherein the ratchet teeth are configured to move the adjustment member in a direction away from the fixing member in response to each predetermined increment of rotation of the adjustment member in the direction of winding the torsion spring and to allow the torsion spring to move the adjustment member into abutment with the fixing member after each increment of rotation to generate an audible abutment sound.

13. The spiral balance device according to claim 12; wherein each ratchet tooth has a slant face slanting in a circumferential direction of the pipe and a stepped portion at one end of the slant face.

14. The spiral balance device according to claim 11; wherein the adjustment member has a projection that extends upwardly through an opening at the center of the fixing member, the stopper spring being disposed around the projection.

15. The spiral balance device according to claim 14; wherein the projection has an enlarged-head section, and the stopper spring is interposed between the enlarged-head section and the fixing member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a cross-sectional view of a spiral balance device according to one embodiment of the present invention.

(2) FIG. 2 is a disassembled perspective view of an upper end portion with the pipe omitted.

(3) FIG. 3 is an enlarged cross-sectional view of an anchor portion.

(4) FIG. 4 is a perspective view of a fixing member as seen from the bottom.

(5) FIG. 5 is a partly cutaway perspective view of an adjustment member as seen from the bottom.

(6) FIG. 6 is a cross-sectional view of an adjustment member.

(7) FIG. 7 is a bottom view of the adjustment member.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows an example of a spiral balance device according to one embodiment of the present invention to be applied to a sash window (not shown). As conventionally known, a pipe 1 configured to be housed in a window frame (not shown) of a sash window opens at its upper end and lower end and is fixed to the window frame by inserting a mounting screw (not shown) into a mounting hole 2 disposed near the upper end. At the lower end portion of the pipe 1, a coupling 3 is rotatably installed. Within the pipe 1, a spiral rod 5 having a screw section 4 formed in an axial direction is housed, and the spiral rod 5 extends in an axial direction through a slot at the central portion of the coupling 3. A first terminal or end portion 6 of the spiral rod 5 extends to near the upper end of the pipe 1, and a second terminal or end portion 7 of the spiral rod projects downwardly from the lower end of the pipe 1 and has a pin 8 attached thereto for connection with a window (not shown).

(9) A cylindrical anchor 9 is inserted into the upper section of the pipe 1 and fixed to the window frame by the mounting screw (not shown). As shown in FIGS. 2 and 3, the anchor 9 has a large diameter portion and a small diameter portion formed below the large diameter portion. A torsion spring 11 extends axially inside the pipe 1. The upper end portion of the torsion spring 11 is fixed to the small diameter portion of the anchor 9 and the lower end portion of the torsion spring is fixed to a cylindrical sleeve 10 which is connected to the coupling 3. In the disclosed embodiment, the coupling 3 and the sleeve 10 are formed as one piece though they may be formed as separate pieces connected together to form an integrated structure. As conventionally known, the lower end of the spiral rod 5 is fixed to a connecting member (not shown) fixed to the window. As also conventionally known, a slide block (not shown) may be fitted to a window frame, and the lower end of the spiral rod may be connected to the slide block to connect the spiral rod to the window via the slide block. Here, the pipe may be connected to the window side and the spiral rod may be connected to the window frame side.

(10) With reference to FIG. 2 and FIG. 3, the large diameter portion of the anchor 9 is provided with engagement holes 12 aligned with the mounting hole 2 of the pipe 1 and slits 13 which extend in an axial direction and open at their upper end. When the mounting hole 2 is formed in the pipe 1, a part of the wall of the pipe is pressed inwardly, forming a burr (not shown) that engages with the edge of the engagement hole 12. By this structure, the anchor 9 is fixedly held in the pipe 1 and will not be detached from the pipe. A fixing member 14 is inserted into the large diameter portion of the anchor 9, and outward projections 15 formed at both sides of the fixing member engage with the slits 13 to prevent rotation of the anchor 9 relative to the fixing member 14. An axial hole 16 opening in the axial direction of the pipe 1 is formed at the center of the fixing member 14.

(11) Into the small diameter portion of the anchor 9 which extends downwardly from the fixing member 14, an adjustment member 17 is rotatably disposed. The adjustment member 17 has a cylindrical body having an outer diameter slightly smaller than the inner diameter of the small diameter portion of the anchor 9, and at its upper face, a spring-retaining projection 18 projects upwardly into the axial hole 16 of the fixing member 14. At the front end of the projection 18, an enlarged-head section 19 is disposed. A stopper spring 20 is disposed around the projection and urges the adjustment member 17 to be pressed against the underside of the fixing member 14. The stopper spring 20 is inserted between the enlarged-head section 19 and the upper edge of the axial hole 16 of the fixing member 14, and in FIG. 3, it urges or pulls the adjustment member 17 upwardly. If desired, the stopper spring may be eliminated since the spiral rod 5 is urged to the side of the first terminal 6 by the spring force of the torsion spring 11 and presses the adjustment member 17 upwardly.

(12) As shown in FIGS. 5-7, engagement projections 21 are disposed at the inner face of the adjustment member 17. In this embodiment, the engagement projections 21 comprise two generally triangular protrusions facing each other and each projecting inward from the inner face of the adjustment member 17. The lower face of each engagement projection 21 slants toward the central portion of the adjustment member as shown in FIG. 6, and both side faces slant in a generally truncated triangular shape when viewed from the bottom as shown in FIG. 7. When the first terminal 6 of the spiral rod 5 is inserted into the inside of the adjustment member 17, the torsion spring 11 urges the first terminal 6 into engagement with one of the side faces of the engagement projections 21. For example, if the torsion spring 11 is wound by turning the spiral rod 5 in the counterclockwise direction, the restoring force of the torsion spring urges the spiral rod clockwise to position A. To wind the torsion spring 11, the spiral rod 5 is turned counterclockwise to position B where it engages the other side faces of the engagement projections 21 after which continued rotation of the spiral rod rotates the adjusted member 17. When the torsion spring 11 is wound to the desired pre-tension and rotation of the spiral rod 5 ceases, the restoring force of the torsion spring turns the spiral rod clockwise to position A. As explained above, without withdrawing the spiral rod 5 out of the pipe 1, the adjustment member 17 can be rotated to tighten the torsion spring 11 by simply gripping and rotating the second terminal 7 of the spiral rod 5 that protrudes from the lower end of the pipe.

(13) With reference to FIG. 2, FIG. 4 and FIG. 5, between the fixing member 14 and the adjustment member 17, namely between the upper face of the adjustment member 17 and the lower face of the fixing member 14 in FIG. 2, a ratchet mechanism is disposed which allows the adjustment member 17 to rotate when the spiral rod 5 is rotated in a winding direction that winds the torsion spring 11 and prevents the adjustment member 17 from rotating when the spiral rod 5 is rotated in the opposite direction that unwinds the torsion spring.

(14) In this embodiment, the fixing member 14 has four ratchet teeth 22a and the adjustment member 17 has four corresponding ratchet teeth 22b. Each ratchet tooth 22a,22b has a slant face 23a,23b which slants in the circumferential direction of the pipe 1 and a stepped portion 24a,24b at the end portion of the slant face. In a rest state (FIG. 3), the ratchet teeth 22a,22b engage one another, i.e., the slant faces 23a engage with the slant faces 23b and the stepped portions 24a engage with the stepped portions 24b.

(15) When the adjustment member 17 is rotated counterclockwise in the direction of the arrow shown in FIG. 2, the slant faces 23b of the adjustment member 17 slide along the slant faces 23a of the fixing member 14. As the elevated parts of the slant faces 23b approach the elevated parts of the slant faces 23a, the adjustment member 17 is moved downwardly against the biasing force of the stopper spring 20. As the adjustment member 17 is further rotated in the winding direction, the stepped portions 24b slide over the stepped portions 24a of the fixing member 14 at which time the stopper spring 20 rapidly pulls the adjustment member 17 upwardly causing the slant faces 23b to abut the slant faces 23a. The rapid abutment of the ratchet teeth 22a,22b generates a snap or click sound indicating that the torsion spring 11, which rotates with the adjusting member, has rotated one increment in the winding direction. By repeating this operation, the torsion spring 11 can be wound to a predetermined pre-tension state by simply counting the number of snaps or clicks generated during rotation of the adjustment member 17. After each incremental rotation, the adjustment member 17 is prevented from rotating in the reverse direction that would unwind the torsion spring 11 due to engagement of the stepped portions 24a,24b.

(16) In the described embodiment, the ratchet mechanism is disposed on the lower surface of the fixing member 14 and the upper surface of the adjustment member 17. The invention is not limited to this arrangement and, for example, the ratchet mechanism may be disposed on the circumferential side faces of the adjustment member and fixing member.

(17) By the above structure, after incorporating the respective members into the pipe 1, and without withdrawing the spiral rod 5 out of the pipe, the adjustment member 17 can be rotated and the torsion spring 11 can be wound by exerting rotation by use of the second terminal 7 under such condition that the first terminal 6 of the spiral rod 5 is engaged with the adjustment member 17. Thus, the spiral balance manufacturers can provide window manufacturers with the spiral balance devices in such a condition that pre-tension is preliminarily applied by winding the spring with a predetermined number of rotations. At that time, at each time of rotation, the snap or click abutment sound is generated with the ratchet teeth 22a, 22b, whereby the number of rotations can be confirmed. If the spring is overly wound, the spiral rod 5 may be put in a free state by pulling the spiral rod 5 downward to disengage the first terminal 6 from the engagement projections 21 of the adjustment member 17. As a result, the spiral rod 5 and the coupling 3 can freely rotate, whereby the torsion spring 11 is released. Afterward, by elevating the spiral rod 5 to place the first terminal 6 into engagement with the engagement projections 21, the winding operation can be made again by rotating the spiral rod.

(18) In the above examples, the present invention is applied to a sash window, but the present invention may be applied to other windows, sliding doors, and various apparatuses with opening or closing operation.