US2826781A

US2826781A - Adjustable foot mechanism for sash balances

Info

Publication number: US2826781A
Application number: US581888A
Authority: US
Inventors: William E Gency
Original assignee: UNIQUE BALANCE CO
Current assignee: UNIQUE BALANCE CO
Priority date: 1956-05-01
Filing date: 1956-05-01
Publication date: 1958-03-18
Anticipated expiration: 1975-03-18

Description

March 18, 1958 w. E. GENCY ADJUSTABLE FOOT MECHAbiISM FOR SASH BALANCES Filed May 1, 1956 2 Sheets-Sheet 1 INVENTOR. WiLLlAM E. GENCY fi/s A March 18, 1958 w. E. GE-NCY ADJUSTABLE F OOT MECHANISM FOR SASH BALANCES 2 Sheets-Sheet 2 Filed May 1, 1956 INVENTOR. WILLlAM E. GENCY I I I I I I 1 1 BY I 2,826,781 ADJUSTABLE FooT MECHANISM FOR SASH BALANCES William E. Gency, Old Greenwich, Conn., assignor to Unique Balance (10., New York, N. Y6, a corporation of Illinois Application May 1, 1956, Serial No. 581,888

Claims. 01. 16-197) This invention relates to mechanisms by means of which the tension of the springs of spiral sash balances may be adjusted and, more particularly, to devices of dow, and the central helical spring being in cooperative.

relationship with the spiral rod so as to exert its counterbalancing effect without elongation. Various mechanisms have heretofore been designed to permit of adjustment of the tension of the innermost helical spring in these balances. These previously suggested adjusting mechanisms, however, have been inadequate to satisfy the requirements of the trade, either because of themherent diificulty of manipulating them or because the location of the mechanisms has rendered them inaccessible after the balances have been installed.

An object of the present invention, accordingly, is to provide a mechanism by means of which the spring tension of the inner helical spring of the spiral sash balances of the above character may be readily adjusted after the balance has been installed.

Another object of the invention is to provide an adjusting mechanism of the above character which may be inexpensively manufactured and conveniently installed.

The foregoing and other objects and advantages are attained by providing an adjusting mechanism that may be incorporated in or carried by the structure of the foot plate, the mechanism being so formed as to permit of adjustment by the application of a tool such as a screw driver thereto from a position directly beneath the foot plate. Furthermore, the mechanism utilizes a ratchet and pawl connection normally biased to engaging position by a spring which is released by initial axial movement of the screw driver, prior to the turning movement which effects the desired adjustment of the tension of the centrally disposed balance spring.

In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, wherein:

Figure 1 is an exploded view of an adjusting mechanism constructed in accordance with the present invention, this view illustrating the various parts in axial alignmm;

Figure 2 is a perspective view of the adjusting mechanism of the :present invention shown with the spiral rod projecting therethrough, as in the operation of the'm'e'chanisrn;

Figure 3a is a view, partly in section, as seen from a point below the mechanism looking upwardly, during its assembly;

atent Q "ice Figure 3b is a view similar to Figure 3a showing the mechanism after it has been assembled;

Figure 4 is a sectional view taken on a plane indicated by the line 4-4 of Figure 5 and looking in the direction of the arrows;

Figure 5 is a sectional view taken on a vertical plane passing through the axis of the mechanism; and

Figure 6 is a sectional view taken on a vertical plane indicated by the line 6--6 of Figure 4 and looking in the direction of the arrows, showing how the mechanism permits the adjustment of the central helical spring.

Referring to Figure 5, there is shown a convention-a1 two-spring spiral sash balance having a top hanger 10 towhich'there is secured the upper end of an outer helical spring 11, the latter being encased in the tubing 12. Within the hanger 10 and the outer spring 11 there is mounted a spiral rod 15 having, at its upper end, a loop 16. An eyelet 17 passes through the tubing 12, the hanger 10 and the loop 16, and a screw nail or other fastening device 20 passes through the eyelet 17 and is secured to the window frame 21 as shown, all in accordance with known practice.

In the annular space between the centrally mounted spiral rod 15 and the outer helical spring 11, there is provided an inner helical spring 22 mounted on and in frictional engagement with a short section of tubing 25 at the upper end of the inner helical spring. The spring 22 is substantially inextensible axially, but its upper end may be rotated by the application of a-suificient torque thereto. The tubing 25 has an integral slotted nut 26 at its upper end, which follows the spiral configuration of the rod 15 as the window is raised and lowered and thereby supplies the additional counterbalancing force 'the window is raised and lowered, as heretofore explained.

However, the structure described thus far is conventional and the present invention, which is directed to a novel mechanism for adjusting the tension in the'inner helical spring 22, will now be described.

Referring to Figures 1 and 2, the long plate 3650f the foot plate 27 is secured by a rivet 37 to a short plate 49. The plate 40 has an extension 41 at one end, forming a pawl plate with a central aperture 55 and two upstanding diametrically op-posed pawl teeth 58, to be described in greater detail hereinafter. At the opposite end of the short plate 40, a stop 42 is provided, which projects through the opening 45 in the long plate 36 for the purpose to be described hereinafter.

The adjusting member of the mechanism is shown in perspective in Figure l at 46. It is provided, at its lower end, with a flange or plate 47 having a slot 50 and an open center sufficiently large to accommodate the spiral rod i5. Above the flange 47 there is a trunk 43 which has an open center to accommodate the spiral :rod

15, but a smaller outside diameter than the flange. .As

as that of the lower portion of the adjusting member so as to accommodate the spinal r0d1'5.

The-long plate 36 is provided, at its upper terminus, I,

with a sleeve 52 which is slightly tapered toward the end and adapted to be inserted into the lower end of the outer helical spring 11, thereby to hold the spring by friction.

The flange portion 47 of the adjusting member 46 is adapted to seat on the lower surface of the pawl plate/t1, with the trunk 48 fitting snugly but rotatably inside the aperture 55. The tubular extension 51, is housed with a loose fit within the sleeve 52, the extreme upper. end of the tubular extension projecting beyond the sleeve, as shown in Figure 2 so as to engage frictionally the lower end of the inner helical Spring 22 in much the same way that the sleeve 52 engages the outer helical spring 11.

A ratchet plate or-washer 56 having two oppositely placed notches or recesses 57 is seated onthe upper surface of the plate 41, the notches 57 providing 1ratchet teeth, and the ratchet plate being placed so that the notches 57 normally engage the pawl teeth 58 of the plate 41 to maintain the torsional stress in the inner helical spring .22. The ratchet plate 56 is also provided with two diametrically opposed, inwardly extending teeth 60 projecting into the slot 50 of the adjusting member 46.

The teeth 60 thereby provide an operative relationship 1 between the pawl plate 41 and the adjusting member 46 so as to maintain the desired helical stress in the inner spring 22 which, in turn, helps provide a component of the force which supports the window.

A helical spring 61 is seated on the underside of the collar 52 and presses against the upper surface of the ratchet plate 56 to maintain the ratchet plate and the pawl plate 41 in operative relationship with each other. A convenient self-contained sub-assembly consists of the assembled long and

short plates

36 and 40, the adjusting member 46, the ratchet plate 56 and the spring 61. With the spring 61 and the ratchet plate 56 in position, the teeth 60 being in alignment with the slot 50 in the adjusting member 46, and the latter in turn in alignment with the rivet head 37 as shown in Figure 3a, the adjusting member 46 is projected through the opening 55 in the plate, 41, the opening in the ratchet plate 56, and the central portion of the spring 61, thence through the sleeve 52. After the plate 47 of the adjusting member 46 has cleared the rivet head 37, the adjusting member 46 is turned through anangle ,of approximately 90 degrees, whereupon the, ratchet plate 56 will snap into engagement with the pawl teeth 58 of the pawl plate 41. At this point, however, the slot 50 of the adjusting member 46 will no longer be in alignment with the rivet head 37 and hence the adjusting member 46 will not be able to slide downwardly past the rivet 37. The sub-assembly is then complete. The sub-assembly maybe assembled with the two helical springs 11 and 22 as shown and described herein, at the factory or at the time it is installed on the window.

The adjusting mechanism of the invention, whether it be the sub-assembly or the complete assembly, is installed on the window by locating the projecting stop 42 at the corner of the window, as shown in Figure 5, and thereafter bending the lower portion of the long plate 36 through an angle of 90 degrees, hammering the teeth 31 into the bottom of the sash and securing the screws 35 in position in the holes 30.

The adjustment of the tension of the spring 22 is accomplished by inserting the bit of ascrew driver (indicated in phantom in Figure 6) into the slot 50 in the plate 47. If the tension of the spring 22 is to be increased, then the screwdriver need only be turned in a counterclockwise direction, as viewed from below in Figures 3a and 3b. This will cause the ratchet plate 56 to be moved in a corresponding direction and the pawl teeth 58 will force the plate upwardly (with the washer teeth 60riding in the slot 50 to maintain engagement with the adjusting member) to disengage the teeth from the notches 57.3. Continued rotation through 180 degrees will cause the notches 57 to snap into position with respect to the pawl teeth 58 and thus prevent unwinding of the spring. Continued motion of the type above deturn stages of the plate 56. 2O

4 scribed will cause further increase of the tension of the spring.

If the tension of the spring is to be decreased, a screwdriver or similar instrument having a bit small enough to fit within the opening 55 of the plate 41, but large enough to engage the inwardly-extending teeth 60 of the ratchet plate 56, is used. The screwdriver is first moved axially (upwardly in Figures 1-4, inclusive) to cause the bit to engage the bottom of the teeth 60 and push the plate 56 upwardly until the notches 57 disengage the teeth 58. At this instant the tension of the spring 22 will tend to cause the plate 56 to move in a clockwise direction, as viewed from below in Figures 3a and 3b. This motion is resisted to the extent desired by the operator and sufficiently to permit the gradual release of the spring tension. It will be understood, of course, that the pressure of the coil spring 61 will normally permit this releasing motion to takeplace in half- If continued release of tension is desired, then the screwdriver must be urged upwardly to maintain the plate 56and its notches 57 out of engagement with the pawl teeth 58.

I claim:

1. An adjusting mechanism for spiral sash balances having a spiral rod and a helical spring with a slotted nut engaging the spiral rod adjacent one end of the spring, comprising a first plate carried by the foot plate of said balance, said first plate having a central aperture therein, an adjusting member rotatably mounted below the first plate, said adjusting member having an open center and an extension with an open center, said extension passing through the aperture in the first plate and adapted to engage the helical spring adjacent the end remote from said slotted nut, the central opening of said adjusting member and extension being adapted to permit the spiral rod to project therethrough, a second plate above the first plate and surrounding the extension of the adjusting member having means to engage said extensionof the adjusting member, a ratchet and pawl mechanism between the plates, means to maintain said ratchet and pawl mechanism in operative relationship, and means on said adjusting member to enable it to be turned by a suitableinstrument.

2. A device according to claim 1 wherein the means to maintain said ratchet, and pawl mechanism in operative relationship is a helical spring surrounding the ad justing member. 1

3. A device according to claim 1 wherein the adjusting member is so formed that the instrument for turning it may, when in operative position, disengage the ratchet from the pawl and thereby permit the lowering of the tension in the helical spring.

4. A device according to claim 1 wherein said extension is a tube over which the helical spring fits to hold said helical spring.

5. A device according to claim 1 wherein the portion of said adjusting member below said first plate is a plate having a slot to enable it to be turned.

6. A device accordingtoclaim 5 wherein the foot plate has a ridge of a size and location such that the ridge normally retains the adjusting member captive by restricting the axial movement of the adjusting plate, but the adjusting member may be turned to a position where the slot will pass over the ridge and permit the assembling and the disassembling of the mechanism.

7. A device according toclaim 5 wherein said adjusting member-engaging means comprises a pair of diametrically opposed teeth extending into the slot of the adjusting member, adapted to be contacted from below through said slot by the bit of a screw driver to disengage the ratchet plate from the pawl teeth and thereby permit the lowering of the tension in the helical spring.

8. A device according to claim 1 wherein the ratchet mechanism comprises at least one pawl tooth on the first plate and said second plate is a circular ratchet plate having at least one tooth thereon.

9. A device according to claim plate is formed with at least one the slot of the adjusting means.

10. An adjusting mechanism for two spring spiral sash balances having the outer concentric helical spring and the spiral rod secured to the window frame and the inner concentric helical spring provided with a slotted nut engaging the spiral rod adjacent one end of the latter spring, comprising a first plate carried by the foot plate of said balance, a sleeve carried by said foot plate adapted to hold the lower end of the outer helical spring, said first plate having a central aperture therein and two pawl teeth thereon, an adjusting member rotatably mounted on the first plate and having a slot formed therein enabling it to be turned, said adjusting member having an open center and an extension of tubular form passing through the aperture in the first plate and through said sleeve and adapted to engage the inner helical spring 8 wherein the ratchet tooth projecting into adjacent the end remote from the said slotted nut, the central opening of said adjusting member and extension being adapted to permit the spiral rod to project therethrough when the window is raised, a ratchet plate above the first plate having two notches forming two ratchet teeth adapted to engage said pawl teeth and having a pair of diametrically opposed teeth extending into said slot to engage said adjusting member, and a spring above said ratchet plate adapted to engage said ratchet plate andthereby maintain said ratchet plate in engagement with said first plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,926,951 Larson Sept. 12, 1933 2,565,804 De Vries et al. Aug. 28, 1951 2,602,958 Brown July 15, 1952 2,622,267 Peremi Dec. 23, 1952 2,633,600 Larson Apr. 7, 1953