As illustrated in
My solution to this problem is best understood by reference to
End cap 120A serves two general purposes. First, it is necessary, and is used, to hold hook 610 in functional position (as shown in the drawing figures). Without end wall 125 and end wall extension 125A, hook 610 would be pulled by pressure on cord 600 around bottom pulley 501 to a position on the other side of extended travel channel 101 adjacent back 101A. In addition, it has been found that versions of spring 200 with greater tension require not just dorsal hooks 901 on pulley mounting end 900A (which hook onto the back 101A of extended travel channel 101 at bottom cut-out 120C) for proper stabilization, but lateral hooks 902 anchored in the positions shown. Lateral hooks 902 could be mounted directly to extended travel channel 101, but by mounting them to end cap 120A via mounting ledges 121 they also serve to hold the end cap 120A firmly in position so that it can accomplish its functions as part of the design.
Bottom pulley mounting end 900B provides a mount for fixed pulleys 400, which are connected by cord 600 to spring 200 via middle carriage pulleys 300. Hence, all of these parts are under tension provided by spring 200. In contrast to these tensioned parts, extended travel bottom guide 801 is not under tension. It is connectable intermediate top guide 700 (which is located at first end 110) and extended travel bottom roller 501 (which is located at second end 120). The bottom guide 801 is, as illustrated, preferably configured so that it straddles the intermediate tensioned connector 900C of the end carriage via slot 801C when it is inserted into and connected to channel 101. A bottom guide fastener 802 can be passed through channel openings 102, bottom guide openings 801D, and connector openings 900D to connect the bottom guide 801 to extended travel channel 101. Channel slots 101D are provided in the back 101A of extended travel channel 101, allowing dorsal extensions 801B to be inserted therethrough when the bottom guide 801 is inserted into channel 101. Once dorsal extensions 801B are locked into channel slots 101D and bottom guide fastener 802 is passed through bottom guide 801, it is firmly and rigidly held in position, allowing it to serve its purpose in interfacing with a window sash. This configuration can also serve to further stabilize extended member 900 and its connected parts.
As previously noted, my invention allows the easy substitution of top and bottom guides as needed for particular applications in constructing balances. Thus, my invention can be used with top guides and bottom guides that are configured in various ways, such as with or without lateral extensions 700A, 800A, 801A, or that have different critical dimensions as necessary for different sizes and types of window sashes. These and numerous other variations are possible without exceeding the scope of the inventive concept. Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
1 Block and tackle window balance (Prior Art)
2 Extended travel block and tackle window balance
100 U-shaped channel
100A Back of U-shaped channel
100B Sides of U-shaped channel
101 Extended travel channel
102 Channel openings
101A Back of extended travel channel
101D Channel slots
110 First end of channel
120 Second end of channel
120A End cap
120B Corner cut-outs
120C Bottom cut-out
121 Mounting ledges
122 Terminal end
125 End wall
125A End wall extension
200 Balance spring
300 Moveable pulleys of middle carriage assembly
400 Fixed pulleys of end carriage assembly
500 Bottom pulley
501 Extended travel bottom pulley
600 Balance cord
610 Jamb mounting hook
700 Top guide
700A Lateral extensions
800 Bottom guide
800A Lateral extensions
800B Dorsal extensions
801 Extended travel bottom guide
801A Lateral extensions
801B Dorsal extensions
801C Slot in bottom guide
801D Bottom guide openings
802 Bottom guide fastener
900 Extended member of end carriage assembly
900A Roller mounting end of extended member extended carriage assembly
900B Bottom pulley mounting end of end carriage assembly
900C Intermediate connector of end carriage assembly
900D Connector openings of end carriage assembly
901 Dorsal hooks of end carriage assembly
902 Lateral hooks of end carriage assembly