US2795810A - Sash balance - Google Patents

Description

June 18, 1957 J DECKER ETAL 2,795,810

SASH BALANCE Filed Nov. 30, 1954 2 Sheets-Sheet 1 FIG. 2.

FIG.1.

FIGS.

INVENTORS lidnck U? Detlrer BY Mala/on H. Greg? June 18, 1957 F. J. DECKER ETAL 2,795,810

SASH BALANCE 2 Shets-Sheet 2 Filed Nov. 30, 1954 ATTO States 2,795,810 SASH BALANCE Frederick J. Decker, Pittsford, and Mahlon H. Gregg,

Rochester, N. Y., assignors to The Caldwell Manufacturing C0., Monroe County, N. Y., a corporation of New York Application November 30, 1954, Serial No. 472,156 4 Claims. (Cl. 16-198) This invention relates to spring sash balances and is particularly directed to an adjustable balance of this character, which is an improvement over previous balances of cable is secured to the periphery of the drum and provided at its free end with a device for attachment to a sash. With the outer end of the cable held from entering the housing the spring is wound up and the axle set by a ratchet or some other form of locking device.

In some of the forms of prior devices of this character the tension is permanently adjusted at the factory. In others there have been forms of ratchet adjustments provided whereby the axle may be rotated and reset relative to the cable drum to increase or decrease the spring ten- SlOIl.

Spring sash balances in general are devices attachable to the frame of double-hung window sash, one balance operating with a lower sash, movable upwardly to open position, and another balance operating with an upper sash movable downwardly to open position, each sash being slidable between suitable guides. The springs of such balances are wound or tensioned to a required extent when their respective sashes or window members are in their normal closed position, the tension decreasing when either sash is moved to its closed position.

Spring sash balances which were formerly on the market were provided with fiat metal tapes to carry the sash. Such types did not have the required life, and in later years it has been common to use slender cables rather than tapes. The cables, however, had a tendency to pile up irregularly on the drivers or reels on which they were arranged to be wound, which sometimes resulted in shortened life of the cables.

One object of the present invention is to provide a construction in which the cables will lay themselves on the receiving reels or drums in closely juxtaposed turns, making a closed helix, without requiring grooves or guides cut into the peripheries of the drums.

Another object is to permit the use of inexpensive cast metal parts requiring a minimum of machining, the plates being extremely simple to assemble and install.

Still another object of the present invention is to provide a nylon or slipbearing over which the cable is run from the drum to the attachment on the sash, said bearing having a sufficiently large radii and hence supplying a large enough bearing surface so that the cable moves over said bearing with a minimum of frictional resistance. In the conventional constructions of this type a cable roller is used, the roller of necessity being so small in diameter that the life of the cable is considerably shortened, due to the sharper angle of its. bend over the roller.

The construction of a preferred form of the invention, and its manner of use may best be understood by reference to the accompanying drawings, in which Fig. l is a top plan of a sash balance embodying the novel features of the invention, the cover plate being removed;

atent Referring first to Figs. 1 and 2, the device as illustratedhas its working parts enclosed in a metal housing, designa-ted H in the drawings, and approximately rectangular in form. This may be a casting, as indicated, or may be stamped from sheet material. In the drawing, the housing has a flat bottom, or back plate 10, having an upwardly extending rim 12. A cover plate or closure 14 is sized to fit within the rim 12, and hollow bosses 16 preferably integral with. the bottom or back plate 10, extend through openings 18-. in the plate 12, the latter being positioned by shoulders 20 on the bosses 16. The plate 12 is retained on the bosses (after the inner members are in place), by. staking or upsetting the projecting, ends of'the bosses 16 against suitable chambered recesses around the openings 18 (Fig. 2).

It will be noted that the bosses 16, two of which are provided in each unit, suitably spaced, are not normal to the general plane of the housing bottom 10, i. e. not at a angle, but are disposed at an angle thereto which differs from a right angle by about 3 or 4 degrees. The purpose of this angular relation of the bosses 16 is to assure the required closed-helix winding of the sash suspension cables as aforementioned, as the bosses 16 constitute fixed pintles or hubs on which the cable drums may rotate, as will be presently described.

It will be noted in Fig. 2 that each boss carries a cuplike drum, designated generally by the characters D and D, having a bottom 22 and a circular rim 24, the top of the drum being open. The bottom 10 of the housing H, and the lower face of the cover plate 14 are recessed at 26 and 28, respectively, to closely conform to the dimensions of the drums to constitute alignment guides, so that the drums will not wobble on the supporting bosses 16.

Each of the drums has an inturned lug 30 with which a hooked end 32 of a spiral fiat metal spring 34 engages. The inner endo-f each spring 34 is hooked at 38 into a slot 40 provided in each of the drum support bosses 16. Obviously, when the drum D is turned counter-clockwise (as'viewed in Fig. l) the tension or torque effect thereof will be increased, tending to turn the drum D clockwise when and if it is permitted to unwind. Similarly, the spring 34 in drum D" tends to turn the latter in a counterclockwise direction (as viewed in Fig. 1) when it unwinds.

It should be understood that the winding of the springs occurs when either the upper or lower sash of a double hung window are moved downwardly, and the unwinding occurs when either sash is moved upwardly, the springs therefore tending to support the sash by providing a countergravitational force. The springs, which are supplied with the unit, are selectedto nearly support the sash in a window in which the complete spring balance is installed.

The drum D. is provided with a cable or flexible wire C, and the drum D" is similarly provided with a cable C. One end of each cable enters a perforation in the rim of a drum. and is secured by a suitableclip 42..

From the drums, the cables D and C" extend to one end of the housing H, and then around a semicircular slip bearing, or guide 44, grooved at 36 to suit the cables, that is set in a correspondingly shaped channel 46 in the housing H. This guide is a preferred substitute for the pulley that is usually included at this point in former structures, and is thought to be one of the novel features of the instant invention, both from the consideration of more satisfactory operation and long service, and as a cheaper item of construction, requiring no maintenance whatever. A preferred material for this guide is the well-known plastic marketed under the trade name nylon. This material has been found entirely satisfactory in normal use for the purpose above described,

It will be noted (Fig. 2) that the angular disposition of the bosses 16, in relation to the paths of the cables C and C" from the guides 44 to the cable drums D and D" tends to keep the successive convolutions of the cables from piling up on one another as the drums revolve during the windup of the cables, and therefore at all times the portions of the cables remaining on the drums are in close contact, one turn to the next, and are as accurately disposed as they would be on a drum with grooves so placed.

We have found that an angle of 93 has been satisfactory. However, this may be increased within a range of depending upon the particular size and type of cable and the size of the drum employed. An angle of at least 91 is necessary to give satisfactory operation.

Means are provided to permit either sash of a window to be rendered immovable toward its open position. Adjacent portions of the housing that surround the channels 46 are L-shaped pieces of metal 48 that are guided lugs 50 that project downwardly from the cover plate 14 to serve to hold these pieces 48 against the bottom of the housing H. Extensions 52 and 54, beveled at their free ends, terminate at a point (Fig. 1) where they are almost, but not quite, caught between the straight portions and the helically-wound portions of the cables. Lugs 56 extending on each piece 48 through the slots 58 in the housing. These lugs therefore lie in recesses 60 and may be reached easily when the device is in its installed location (Fig. 7). A slight movement of one or the other of these lugs toward the drums will cause the extensions 52 or 54 to become wedged against the cables at W and will prevent their respective drums from rotating on the bosses 16 in the unwinding direction.

The spring torque will draw metal pieces 48 and extensions 54 in under the cable forcing it against the casing, thereby locking the rotation of the drum to the extent that the lower end of the cable may be detached from the window sash and the sash removed, leaving the cable slack. The window may thus be removed and reinserted without the cable snapping out of reach due to tension thereon. When the cable is again attached to the window and the window is moved downward, the drum reverses and the lock releases to permit regular operation.

Referring now to Figs. 6, 7, and 8, it will be seen that the installation of the spring sash balance-one of which is installed in each upper corner of a window framerequires the head or lintel member L a frame to be recessed or cut through as at 62 to conform to the outline of the housing H, so that a woodscrew 64, passing through a lug 66 on the housing, may retain one end of the device in its required location. A lug 68 on the opposite end of housing H enters a recess that will. be cut into the jam J of the frame, at the end of the head member L, Therefore only one actual fastening per unit is required.

The cable C and C from one unit may extend to a suitable securing stud in either the upper sash S (a portion of which appears in Fig. 6), or to the lower sash not shown.

Inasmuch as drum D will rotate counter-clockwise and drum D" will rotate clockwise when the cables are unwound, it is usually immaterial to which sash either cable is afiixed, as in any case the springs 34 tend to support or balance the sash,

Having thus described a specific embodiment of the present invention as applied to the construction of a particular sash balance, it is to be understood that this form has been illustrated more particularly for disclosing the mode of operation and the principles involved than for limiting the present invention to the specific structure that has been disclosed, audit is to be understood that various modifications, adaptations and alterations can be applied to the specific form shown to be met by the requirements of practice within the scope of the present invention, except as limited by the appended claims.

We claim:

1. A spring balance for window sash comprising a housing having parallel sides, a rotatable flat-surfaced drum mounted on a fixed axis at an inclined angle with respect to said housing, and a flat spiral spring arranged Within said drum and having its ends connected respectively to said drum, and to said inclined fixed axis extending between the sides of the housing upon which said drum rotates, whereby said rotatable drum is actuated, a cable, one end of which is attached to a window sash, and the other end to said drum, said cable being fed onto said drum, said fiat-surfaced drum being rotated on said fixed axis whereby said cable is wound on said drum.

2. A spring balance for window sash comprising a housing having parallel sides, a rotatable flat-surfaced drum mounted on a fixed axis at an inclined angle with respect to said housing, and a flat spiral spring arranged within said drum and having its ends connected respectively to said drum, and to said inclined fixed axis extending between. the sides of the housing upon which said drum rotates, whereby said rotatable drum is actuated, a cable, one end of which is attached to a window sash, and the other end to said drum, said cable being fed onto said drum over a slip bearing, said flat-surfaced drum being rotated on said fixed axis whereby said cable is wound on said drum.

3. A spring balance for window sash comprising a housing having parallel sides, a rotatable flat-surfaced drum mounted on a fixed axis at an inclined angle with respect to said housing, and a flat spiral spring arranged within said drum and having its ends connected respectively to said drum, and to said inclined fixed axis extending between the sides of the housing upon which said drum rotates, whereby said rotatable drum is actuated, a cable, one end of which is attached to a window sash, and the other end to said drum, said cable being fed onto said drum at an inclined angle with respect to said fixed axis, said flat surfaced drum being rotated on said fixed axis whereby said cable is wound on said drum.

4. A spring balance for window sash comprising a housing having parallel sides, a rotatable fiat-surfaced drum mounted on a fixed axis at an inclined angle with respect to said housing, and a flat spiral spring arranged within said drum andhaving itsends connected respectively to said drum, and to said inclined fixed axis extending between the sides of the housingupon which said drum rotates, whereby said rotatable drum is actuated, a cable, one end of which is attached to a window sash, and the other end to said drum, said cable being fed onto said drum, said flat-surfaced drum being rotated on said fixed axis whereby said cable is wound on said drum in a closed-helix pattern.

References Cited in the file of this patent UNlTED STATES PATENTS 23,675 Gladwin Apr. 19, 1859 1,898,584 Mantz Feb. 21, 1933 1,905,107 Kersting Apr. 25, 1933 2,010,214 Braun Aug. 6, 1935 2,191,959 HiIsh Feb. 27, 1940 2,246,086 Austin June 17, 1941 2,304,175 Jessup Dec. 8, 1942 4b: an

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