Abstract: A cord tensioned by a spring supports the sash of a hung window in a stationary position while the sash is tilted for cleaning. The cord pulls a pulley attached to the spring which extends as the sash is further tilted. A tubing houses the spring and pulley and provides a stop that limits the maximum tilt of the sash.

Abstract: A sash window counterbalance spring mounting arrangement for fitment into a channel section within a window jamb, includes coiled ribbon springs; a spring support mounting including a single integral component for locating and supporting the springs, a support for the springs to support and locate the springs on the mounting, and formed by pairs of triangular cross section projections extending from the rear surface of the main body of the mounting such that when the springs recoil rapidly outer surfaces of adjacent springs contact each other, and including an end portion of the main body which is curved, wing projections extending from the front surface of the main body, and an inter engagement element on the longitudinal end of the mounting for cooperative engagement with cooperative inter engagement features on a sash shoe; and a locating arrangement for locating the mounting within the channel section.

Abstract: A balancing spring system for facilitating the opening and the closing of a window sash assembly slidably mounted in channels of opposed window jambs comprises a connector strip. The connector strip has a front surface and a rear surface. The connector strip also has slots extending from the front surface to the rear surface. The connector strip has a connecting head section at a bottom thereof, adapted for connection to the window sash assembly. Curled ribbon springs are adapted to be mounted idle and free to rotate in each of the channels of the window jambs. The curled ribbon springs each have a free end comprising an enlarged head portion at a tip thereof, for connecting the curled ribbon springs to the slots of the connector strip, whereby the curled ribbon springs apply an upward force to the window sash assembly.

Abstract: Disclosed are apparatus for a block and tackle window balance including a terminal clip to be incorporated in single and double hung window assemblies. In one embodiment the terminal clip includes a first end portion defining an opening for passing a terminal end of a cord therethrough, a second end portion disposed remotely from the first end portion, and an intermediate portion including a hook and extending between the first and second end portions.

Abstract: A plug for use in a counterbalancing mechanism of a cable-operated door. The plug is mounted about an overhead shaft and used for operatively connecting the overhead shaft to a torsion spring coaxially mounted thereon. The plug includes a cylindrical collar and a cylindrical flange. The cylindrical collar has opposite first and second portions. The collar is provided with a hooking slot for hooking a free end of the torsion spring therein and the torsion spring has a segment coaxially mounted about the first portion of the collar. The cylindrical flange is rigidly affixed to the second portion of the collar. The flange is used for transferring a torque between the torsion spring and the overhead shaft when the flange is securely fixed about the overhead shaft. The plug further includes a shouldering floor of a given length faced against the hooking slot and extending inside the collar, from the second portion towards the first portion thereof, between the collar and the overhead shaft.

Abstract: The invention is an externally mounted window spring balance device assembly for installation on single or double-hung sash windows either not originally equipped with a counter balance device or on single or double-hung sash windows where the counter balance device has become inoperative due to broken or worn out parts. The externally mounted window spring balance replacement device assembly eliminates the need to disassemble the window frame to access broken or worn out parts located internal to the window frame.

Abstract: The present invention is an apparatus and method of assembling a block and tackle counter balance for windows that reduces the cost of manufacture and installation. In particular, the balance provides vertical support to a window sash using a semi-rigid channel, a top shoe for insertion into one end of the semi-rigid channel, and a bottom shoe for insertion into another end of the semi-rigid channel. Connected to the top shoe is a spring, and a block and tackle pulley assembly is connected between the bottom end of the spring and the bottom shoe, wherein a cord from the pulley assembly extends outward from the bottom shoe for connection to the window sash.

Abstract: Disclosed are apparatus for a block and tackle window balance to be incorporated in single and double hung window assemblies. In one embodiment the block and tackle window balance includes a roller secured within a bottom guide to increase range of travel of a window sash.

Abstract: A threaded follower mounted on a spiral rod is attached to the first end of a torsion spring, the second end of the torsion spring being connected to a window sash, one end of the spiral rod being attached to a window frame by a gear box that prevents rotation of the spiral rod unless the gear box receives externally provided rotational force by which it then rotates the spiral rod.

Abstract: A balancing spring system for facilitating the opening and the closing of a window sash assembly slidably mounted in channels of opposed window jambs comprises a connector strip. The connector strip has a front surface and a rear surface. The connector strip also has slots extending from the front surface to the rear surface. The connector strip has a connecting head section at a bottom thereof, adapted for connection to the window sash assembly. Curled ribbon springs are adapted to be mounted idle and free to rotate in each of the channels of the window jambs. The curled ribbon springs each have a free end comprising an enlarged head portion at a tip thereof, for connecting the curled ribbon springs to the slots of the connector strip, whereby the curled ribbon springs apply an upward force to the window sash assembly.

Abstract: A sash window counterbalance arrangement for counterbalancing the weight of a sash window. The arrangement comprises a sash window spring support mounting located within a channel in a sash window jamb, and a sash shoe slidable in said channel. In use a spring force is generated between said spring support and sash shoe by a spring means to counterbalance the weight of said sash window. The spring mounting comprises at least one mounting peg which projects from said mounting to engage a mounting aperture defined within one of said channel walls to locate and secure said spring support mounting within the channel. The mounting peg is resiliently biassed into engagement with said aperture.

Abstract: A sash window counterbalance arrangement for counterbalancing the weight of a sash window, includes a sash window jamb with a channel defined within the sash window jamb, the channel having a rear wall and a pair of side walls, a sash window shoe slidable in the channel, a spring arrangement connected at one end to the sash window shoe, and a spring support mounting fitted within the channel to support the spring arrangement, the spring support mounting including a locating peg projecting from the spring support mounting to engage a locating aperture defined within one of the channel walls and locate the spring support mounting along the channel, and a self tapping screw fastener engaging the spring support mounting and one of the channel walls to secure the spring support mounting to and within the channel.

Abstract: A sash window counterbalance arrangement for counterbalancing the weight of a sash window includes a spring support mounting locating within a channel in a sash window jamb, a sash shoe slidable in the channel, a spring arrangement which generates a spring force between the mounting and sash shoe to counterbalance the weight of the window, the mounting including at least one mounting peg which projects from the mounting to engage a mounting aperture within one channel wall to locate and secure the mounting, with the mounting secured and located against slidable movement in a first direction due to the spring force, while movement of the mounting in an opposite direction causes disengagement of the mounting peg from the aperture and the mounting peg includes a lip flange which hooks over a portion of the channel wall adjacent the aperture to secure the mounting within the channel.

Abstract: A mount for one or more constant force curl springs uses a mounting block secured within a sash shoe channel to support the underside of a lowermost curl spring with a superposed curl spring mounted to counterrotate against an outer convolution of the lowermost spring. Uncoiled free ends of the curl springs pass downward on opposite sides of the mounting block and connect to opposite sides of a sash shoe arranged below the mounting block. This connection is made by laterally sliding the spring ends into slots molded in the sash shoe so that barbs struck and bent from the planes of the free ends of the springs are lodged in widened recesses of the slots to retain the spring ends against upward withdrawal from the spring slots.

Abstract: The disclosure sets forth an apparatus and method for counterbalancing a roll-up door. A first threaded shaft is concentrically disposed around a torsion shaft and a spring is also disposed around the torsion shaft. The spring has a first end and a second end. The first end of the spring is secured to a first anchor plate that is threadably mounted to thread onto the threaded shaft. The second end of the spring is fixed relative to the torsion shaft. When the threaded shaft is rotated, the first anchor plate moves along the threaded shaft, thereby longitudinally stretching the spring a predetermined distance. A first stop prevents the movement of the first anchor plate along the threaded shaft beyond a predetermined position so that further rotation of the threaded shaft winds the spring thereby applying a predetermined counterbalancing torque on the torsion shaft.

Abstract: A method of securing a torsion spring used in a counterbalance system in which the spring torsion cannot be released without first supporting any existing spring torque utilizes a torsion spring assembly including: a torsion rod extending along a longitudinal axis of and within a torsion spring; an anchor member retaining a first end of the torsion spring with the torsion rod being rotatable about the axis relative to the anchor member; and a winding cone retaining a second end of the torsion spring. The winding cone includes a first winding cone coupling member including a frusto-conical surface retaining the second end of the torsion spring; and a second winding cone coupling member and a fastener. The second coupling member defines an area in which the fastener is received for releasably mounting the second coupling member to the torsion rod. The first coupling member is disposed adjacent and abuts the second coupling member for limited rotational movement between first and second rotational positions.

Abstract: In a counterbalance having a torsion spring which is torqued by a thread follower rotated by axially reciprocal movement of a spiral rod through the follower and into the torsion spring, the pitch of the spiral thread changes continuously, smoothly and consistently at a nonlinear rate according to an equation.

Abstract: Pulleys of a block and tackle window balance include hub steps that interact with other components to reduce the introduction of dirt and dust particles into areas vulnerable to wear. The hub steps of some of the pulleys are recesses formed about the axial bores of the pulleys that mate with protrusions on an axle and a washer. The hub steps of other pulleys are protrusions that abut a support plate and heads of rivets that act as axles. The hub steps allow inverse mounting of the window balance so that the balance can be mounted in a shoe channel for movement with a sash of the window, attached to the sash shoe, and the cord can be attached to the jamb or frame, thus increasing sash travel.

Abstract: A tilt sash counterbalance system has a carrier shoe with a locking cam that moves a locking component to a corner-to-corner locking position within a shoe channel. This is done by moving the locking component to a locked position where the locking component simultaneously increases both the width and the thickness of the carrier shoe. This presses the locking component into one inside corner of the shoe channel while pressing an opposite edge of the carrier shoe in a diagonally opposite direction against a diagonally opposite inside corner of the shoe channel.

Abstract: The assembly comprises an extension spring anchored at one end to a winch mounted to the door opening frame. A double-grooved pulley is mounted on a plate secured to the free end of the spring. A fixed second double-grooved pulley is mounted to the door frame. A pair of cables are anchored at one end to the door frame and extend in parallel to pass around the two pulleys. After the second pulley, the cables separate and extend down to the bottom corners of the door, to which they are secured. Upon release of the door latch with the door down, the spring contracts and, through the first pulley, applies an equal pull to the two cables so that they move at the same rate, thereby raising the door smoothly.

Abstract: A coextruded plastic spring member is disclosed which is bendably disposable between first and second member to create a spring force therebetween. The spring member includes an elongated base formed from a first plastic material which is engageable by the first member. An elongated first spring portion formed from a second plastic material that is resilient and has a predetermined spring characteristic is coextruded with the base member. An elongated second spring portion is coextruded with and extends from the first spring portion and is formed from a third plastic material having a spring characteristic stiffer than that of the first spring portion, with the second spring portion being engageable by the second member. The first and second spring portions are constructed so that the first spring portion is under compressive loading when the second spring portion is bendably engaged by the second member.

Abstract: A block and tackle balance disposed between a jambliner and a window sash includes a spring and a non-rotating pulley system. A head block is disposed on a rod for attaching the balance to the jambliner and securing one end of the spring, and a slide block is disposed at about the midpoint of the rod for securing the other end of the spring. The slide block acts in combination with a base block and a pulley cord, to create the non-rotating pulley system. The slide block and the base block each have at least one cord-receiving channel formed in a raised u-shaped member, for slidably receiving the pulley cord. The base block further includes a bore for securing an end of the pulley cord, and is coupled via the pulley cord to a shoe, which moves in response to movement of the window sash. As the shoe moves, the cord slides within the channels, and the slide block moves toward the base block.

Abstract: A coupling between a twisted rod and a torsion spring of a spiral counterbalance is found to be subject to deformation against the twisted rod from compressive force of the grip of the terminal convolutions of the torsion spring. This problem is solved by using a metal cylinder in the rotation transmission sleeve of the coupling to resist the compressive force and prevent deformation so that the twisted rod can move freely within the coupling. This solution also allows the use of a stronger torsion spring to exert a larger counterbalance force.

Abstract: A jamb liner is mounted in the side jamb tracks of a window frame to mount window units of double hung windows for slidable movement between opened and closed positions. The liner includes transversely spaced channel guides, each guide mounting a guide member that is attached to the adjacent window unit. Flanges are joined to the guides for forming a close fit with the adjacent window unit while, to each guide, there is joined a wing to form a seal with the web of the adjacent jamb to block fluid flow between the window units and the side jamb from one transverse side of the unit sash to the other. The wings of the liner are arcuately curved to transversely diverge from one another in a direction toward the jamb web. The wings are of a substantially greater resiliency than the rest of the liner, said rest of the liner being semi-rigid and made of extruded plastic.

Abstract: An extension spring overhead door system in which the spring may be quickly and easily placed in tension with the door in a closed position. A spring tensioning device is provided which eliminates the need for multiple installers to lift the full weight of the door and then clamp or otherwise prop the door in an open position. An extension spring containment tube is also provided which surrounds the entire periphery of the spring to fully contain the entire length of the extension spring.

Abstract: A jamb liner is provided for a window assembly including a frame and a sash operably mounted in the frame by use of the jamb liner. The jamb liner includes a sash-engaging portion having at least one pair of opposing wall sections and a bottom wall section defining a channel. An air-sealing portion extends from the opposing wall sections for sealingly engaging the frame to prevent undesired flow of air between the jamb liner and the window frame. The air-sealing portion includes a root wall section that extends at an angle to one of the opposing wall sections, a resilient wall section that extends from the root wall section, and a frame-engaging wall section that extends from the resilient wall section. In one form, a pair of the resilient wall sections are provided for supporting the frame-engaging wall section, one extending from each opposing wall section in a bellows-like arrangement.

Abstract: A window balance system for a tilt sash uses a pair of constant force curl springs having curled convolutions carried by sash shoes and free end regions mounted in sash shoe channels above the region of travel of the shoes. The recurl tendency of the springs imparts a lift to the curled spring convolutions, and the shoes transmit the lift to the sash. The springs recurl into the convolutions as the shoes rise and uncurl from the shoes into the shoe channels when the shoes move downward, and neither movement requires the springs to slide frictionally within the shoe channels. Each shoe is preferably formed of two identical halves that are assembled to trap the curl spring along with a cam that locks the shoe when the sash tilts.

Abstract: A load counterbalancing coiled wire spring assembly adapted to provide predetermined nonuniform bending stress induced torsional load supporting force in response to load induced longitudinal spring wire displacement.

Abstract: A mounting element and assembly for a sash frame tensioner used in a sash window frame to support the window in any desired open position, the assembly comprising a channel section member and a sash frame support element slidable in said channel section member. A coiled ribbon spring having a free outer end thereof engaged with said sash frame support member, and a mounting element, the mounting being disposed between the sash frame support member and a coiled body portion of said coiled ribbon spring with a free end of said coiled ribbon spring disposed alongside said mounting, said mounting being secured to said channel section member, directly or indirectly, and in use impinging upon an outer surface of said coiled body portion to retain said coiled body portion in position during uncoiling of said coiled ribbon spring as said sash support member is moved away from said coiled body portion.

Abstract: A window balance system for a tilt sash uses a pair of constant force curl springs having curled convolutions carried by sash shoes and free end regions mounted in sash shoe channels above the region of travel of the shoes. The recurl tendency of the springs imparts a lift to the curled spring convolutions, and the shoes transmit the lift to the sash. The springs recurl into the convolutions as the shoes rise and uncurl from the shoes into the shoe channels when the shoes move downward, and neither movement requires the springs to slide frictionally within the shoe channels. Each shoe is preferably formed of two identical halves that are assembled to trap the curl spring along with a cam that locks the shoe when the sash tilts.

Abstract: A multiple spring counterbalance includes a torsion spring and a tension spring for exerting a combined lifting force on a window sash. A spiral rod is threadably engaged with a follower nut for converting a torque applied by the torsion spring into a lifting force on the window sash. The spiral rod has a pitch that is varied along one part of its length to produce a substantially constant combined lifting force throughout most of a range of sash travel between a lowered position and an intermediate position. However, the pitch is further varied along another part of the length of the spiral member to produce a larger combined lifting force within a remaining portion of the range of sash travel from the intermediate position to the raised position.

Abstract: A jamb liner for a double hung window wherein a length of the jamb liner is mounted to and overlies each of the jamb sides defining the window opening. Each jamb liner has a front profile corresponding to the side of the associated sash to slidably retain and guide the sash. The jamb liner is extruded from a plastic material that is at least semi-rigid. Coextruded on the rear face of the jamb liner is are a pair of longitudinal spring hinge members each having a first portion contiguous with the jamb liner formed from a resilient material having a spring characteristic, and a second portion extending from the first portion formed from a plastic material that is at least semi-rigid. In mounting the window assembly into the jamb opening, the spring hinge members bendably and springably engage the associated jamb sides to generate a uniform biasing force on the sides of the sashes.

Abstract: A coiled ribbon spring comprising a coiled ribbon spring body and, at a free end thereof, a tongue portion having first engagement means for operative connection to an object to be tensioned, said tongue having at a location between said first engagement means and the coiled ribbon spring body, second engagement means co-operable with first engagement means provided on another coiled ribbon spring. Also an assembly of such springs disposed one above the other working in concert e.g. in pairs.

Abstract: This invention, which provides a solution to the long-standing problem of motion-related rattle in torsion balances for windows, is based upon the discovery that the major source of the rattle is related to the movement of the free end of the twisted rod that is mounted within the coil of the torsion spring. A sound-deadening element of resin material is secured to the free end of the twisted rod, being positioned proximate to the extremity of the free end, and the preferred element has a maximum dimension (measured radial to the spring) that is greater than the maximum cross-sectional dimension of the twisted rod but less than the effective internal diameter of the coiled spring. The sound-deadening element eliminates the rattle by preventing contact between the free end of the rod and the spring, and it also acts as a glide to facilitate relative movement between the rod and the spring during operation of the balance.

Abstract: A window noise attenuation device that keeps window balance springs from ratting against the inside of the spring covers when the balance spring is caused to vibrate. The apparatus is designed to be slipped over the window balance spring during the construction of the window. The device can be installed either by hand or by machine. The apparatus features a positioning section that keeps the device substantially fixed in position on the balance spring during use. An offset section holds the balance spring fimly in position away from the walls of the spring cover and jamb liners when the balance spring is caused to vibrate by rapidly closing or opening the window or from other jarring such as slamming a door. The low cost device is designed to last as long as the window spring mechanism.

Abstract: An improved coil spring counterbalance assembly embodying a coil spring support structure that provides a cooperatively radiused restraining shoe against which the uninterrupted smooth external circumferential surface of the coil spring ribbon rotationally operates in extension and retraction thereof during counterbalanced sash movement, thereby eliminating both the clicking sound and spring rotational cyclic vibrational shocks otherwise caused by the spring interior ribbon core tail ending riding over the top of a spring core support hub, in addition to a multiple coil spring connection method for improved successive affixment of extended coil spring ribbons one to the other and in turn to the sash attached balance shoe connector therefor when more than on coil spring is required in order to effect proper sash counterbalancing.

Abstract: A spring balance for counteracting the weight of heavy window sashes includes both a torsion spring and a tension spring. The two springs are separated by a rigid tube. One end of each spring is connected to an end of the rigid tube. A spiral member engages a follower carried by the other end of the torsion spring and includes a stop along its length for engaging an anchor carried by the other end of the tension spring. The spiral member can be attached by conventional means to a shoe or other connection to the window sash.

Abstract: A top clip (20) automatically anchors a window spring (15) at the upper end of a jamb liner spring cover (11) having a generally D-shaped cross section. The top clip has a body (21) that interlocks with the upper coils of spring (15) and has a rounded nose (26) that helps guide the body inside the upper end of spring cover (11). The top of body (21) has a flange (22) that overlaps the upper end of the spring cover, and the periphery of the flange has retainer tangs (25) that extend downward to overlap the outer surface of the spring cover. If a spring is accidentally snapped during assembly, top clip (20) and spring (15) are free to move above the upper end of spring cover (11) and can be returned to an anchored position, simply by pulling downward on the spring and the top clip.

Abstract: A balancing arrangement for double hung windows is disclosed including a spring arrangement supported by a spring holder installed in a window jamb and a balance shoe installed in a window sash. The spring holder is adapted to engage a detent in the balance shoe installed in the top window sash, whereby displacement of the top sash when closed is prevented to maintain a weather stripping seal between the bottom and top sashes at the horizontal center of the window when the bottom sash is lowered for closing against the compression force of the seal. The opening of the top sash is unaffected, other than a slightly greater force being required to bypass the engagement of the detent by the spring holder.

Abstract: A balancing arrangement for double hung windows is disclosed including a spring arrangement supported by a spring holder installed in a window jamb and a balance shoe installed in a window sash. A leaf spring is supported to engage a detent in the balance shoe installed in the top window sash, whereby displacement of the top sash when closed is prevented to maintain the seal between the bottom and top sashes at the horizontal center of the window when the bottom sash is lowered for closing against the compression force of a weather stripping seal at the horizontal center. The opening of the top sash is unaffected, other than a slightly greater force being required to bypass the leaf spring and detent arrangement.

Abstract: A pre-assembled, spring loaded, block and tackle window sash balance assembly is adapted for providing vertical support for a window sash running in an elongated, generally upright sash run having a generally C-shaped guide channel extending along its plow region. The assembly comprises a generally U-shaped housing for a block and tackle spring balance device. The assembly further includes spaced slide means which are discrete from the housing itself and which are slidably interengageable with the guide channel for removeably attaching the assembly to the sash run. Accordingly, the block and tackle balance assembly may be pre-assembled and then conveniently and efficiently attached to the sash run and supported in a position to provide spring balanced support for a window sash mounted in the sash run.

Abstract: A self-contained heavy duty constant force sliding sash counterbalance assembly embodying a stacked plurality of coil springs each having a uniform coiling and recoiling force throughout all of the various coils irrespective of the individual coil spring positions of extension or contraction, wherein the counterbalance assembly structure is provided with an elongated U-shaped housing adapted to adjustably accommodate the addition or removal of individual spring elements as necessary in order to achieve the proper counterbalance effect for the weight of the particular sash to be supported so that over the raising and lowering range of that sash to which the counterbalance assembly is affixed, and at all adjustably set sash opening elevations and corresponding coil spring positions of extension and contraction therebetween, there is a substantially constantly uniform counterbalance force effect exerted on the sash.

Abstract: An apparatus for counterbalancing an overhead door includes a spring anchor assembly adapted to be connected between one end of a torsion spring and a wall of a building at an overhead door opening and a spring winding assembly adapted to be connected between the opposite end of a torsion spring and a shaft rotatably mounted on the wall and coaxial with the spring. The shaft carries a pair of winding drums attached by cables to the bottom of an overhead door. Both the spring anchor assembly and the spring winding assembly have spring attachment means which are adjustable to accommodate different diameters of torsion springs and compensate for the helical form of the spring.

Abstract: A window counterbalance spring (10, 30) enclosed within a spring cover (35) or tube (25) is sound deadened against rattling by having its outer surface (16) coated with a hot melt adhesive (11). Hot melt (11) is preferably sprayed on outer surface (16) of the spring, at it is wound; and for rotationally tensioned springs (10) surrounding twisted rods (20), some hot melt is deposited on the interior (17) of the spring to cushion its vibration against the twisted rod.

Abstract: A system of anchoring a window balance spring (16) in a channel (20) includes an arched anchor plate (10) connectable to spring (16) and having edge projections (15) that fit between the side walls (21) of the channel. When these and the bottom (22) of the channel are supported by a tool (30), anchor plate (10) is stamped flat against the channel bottom to spread edge projections (15) apart and drive them into the channel side walls (21) for a deformation interlock that holds the anchor and the spring reliably in place within the channel.

Abstract: The invention is a force compensation device for use in a spring balanced sash holder for a jamb liner extruded from a durable resin such as polyvinyl chloride, and having a vertical track for containing the sash. Within the vertical track in the sash plow region and running the entire length of the jamb liner is a vertical slotted channel. The lower half of the slotted channel is used to develop frictional force for compensation of spring balance forces. The invention produces its compensating force by frictionally engaging the surfaces of the slotted channel. It comprises two parts, a carrier and a clapper. The carrier supports the weight of the sash, and is supported by the balance spring. The clapper is attached to the carrier. Both the carrier and clapper have braking elements which frictionally engage the surfaces of the slotted channel of the jamb liner track. The carrier and clapper are fastened together at their lower ends but their upper ends are free to move relative to each other.

Abstract: A pulley mount for a window balance system 10 uses a pair of spaced-apart support plates 13 and 14 each having a shoulder rivet 30 with a shaft fitting through a hole 29 in each of support plates 13 and 14. A pair of pulleys 21,23 and 22,24 are mounted on each rivet, with one pulley mounted on the rivet shoulder 32, and another pulley mounted on a flanged bushing 35 around the rivet shaft. A support plate 13 for one pair of pulleys has a hook 12 for connecting to an end of a channel 11 containing the balance system, and a support plate 14 for another pair of pulleys has a coupler 17 connected to a balance spring 15.

Abstract: A window spring system for jamb liners 10 having a guide rails 11 formed in sash run regions 12 includes a spring 40, spring cover 60, spring anchorage 30, and sash platform 50 assembled within spring cover 60 that encloses spring 40 and has a closed back side 61 formed with opposite guide edges 62 shaped to slide into an interlock with guide rails 11 in jamb liner 10. An upper region 66 of the back side of spring cover 60 is cut away to receive spring anchorage 30, which is connected to an upper region of spring 40 and engages spring cover 60 and jamb liner 10 and preferably interlocks with jamb liner guide rails 11. A lower region 67 of the back side of spring cover 60 is cut away to receive sash platform 50 connected to a lower region of spring 40 and also preferably interlocking with guide rails 11 of jamb liner 10.

Abstract: A coupler connects end regions of different sizes of coiled tension springs 30 and 40 to components of block and tackle window balance systems 10. Each coupler 15, 20, or 25 has a snug fit within terminal coils 41 of the strongest spring 40 having the smallest inside diameter, and weaker spring 30 with a larger inside diameter has its terminal coils 31 necked down to fit the coupler. The coupler has a notch or opening with an abrupt edge 18, 22, or 28 axially spaced from an end of the coupler so that the notch is at least twice as long as the largest wire diameter used in the coil springs. At least one of the terminal coils of each spring is indented into the notch or opening in the coupler to a depth of more than one-half the wire diameter so that the indented coil interlocks with edge 18, 22, or 28 and keeps the spring from slipping off the coupler.

Abstract: A sash holder 10 automatically produces sash-holding friction in a resin jamb liner 12 in which the sash 11 runs. Jamb liner 12 has a track 20 in the sash plow region of each sash run 16 and 17, and track 20 is formed within parallel L-shaped edge guides 21. Sash holder 10 includes an upper component 25 connected to a balance spring 13 and a lower component 26 supporting sash 11 in its sash plow region. Overlapping surfaces 39 and 40 of components 25 and 26 form an interferring wedge that operates when the components move vertically to each other in response to spring force pulling upward against the sash weight. The interferring wedge can be arranged in several ways for pressing runners 27 and 28 against track guides 21 to produce sash-holding friction as a function of the vertical extent of the vertical movement of the overlapping surfaces.