1. Field of the Invention
The invention pertains to the field of window sash balances. More particularly, the invention pertains to a carrier for attachment to a window balance.
2. Description of Related Art
Window balance assemblies located in the jamb channels of window frames assist with the raising and lowering of the window sash by providing a counterbalance force to gravity acting on the sash. The window balance is typically fixed at an upper end and is coupled to the window sash by a carrier at the lower end. The carrier moves up and down with the window sash by sliding up and down in a carrier channel in the jamb. The frictional losses caused by the sliding contact between the carrier and the carrier channel increase the forces required to raise and lower the sash of the window.
Spiral balances operate by using a torsion spring wound around a spiral rod to provide the counterbalance force. As the sash is moved up or down, the spiral rod turns, as does the torsion spring. In conventional spiral rod balances, the end of the spiral rod is attached to a carrier that moves up and down the carrier channel as the sash is moved. Because the torsion spring generates increasing torsional forces as the rod is pulled from the carrier, and because the carrier often does not tightly correspond to the size of the cross section of the carrier channel, the carrier tends to “twist” in the channel, thereby creating additional frictional forces between the carrier and the carrier channel.
The carrier assembly preferably includes a carrier, a carrier encasement, and a carrier latch. The carrier is securable to the end of a window balance, including, but not limited to, a spiral rod, an extension spring balance, and a block and tackle balance. The weight of the sash is borne by a sash assembly coupling portion of the carrier. The upward force exerted by the balance on the carrier during opening or closing of the sash is translated into a force urging the carrier toward the sash, and contact is made between the carrier assembly and the side of the sash assembly. The translation of the upward force into a side-directed force eliminates or substantially reduces the friction that might otherwise have been created between the carrier and the carrier channel. In some embodiments, the side-directed force removes the carrier from any contact with the carrier channel, thereby eliminating friction from the carrier rubbing against the carrier channel and even eliminating the need for a carrier channel in the jamb. The translation force may be accomplished in several different ways, including, but not limited to, a pivot, a movement along a ramp, and a camming force.
The lift of the balance applied to the carrier assembly forces the carrier assembly against the side of the window sash assembly to maintain the carrier assembly in a constant relative position with respect to the sash assembly so that the carrier assembly rides up and down with the sash as the sash is raised and lowered. The carrier assembly is pressed against the side of the sash assembly so that the carrier assembly moves with the sash and preferably does not engage a carrier channel formed in the jamb.
The carrier assembly, as used herein, refers to the structure which couples the balance to the window sash assembly. The carrier assembly includes a carrier with a balance coupling portion and a sash assembly coupling portion. These features couple, preferably reversibly to aid in assembly and disassembly, the carrier assembly to the balance and the window sash assembly, respectively. The carrier assembly also includes a sash assembly contacting portion, which is held in contact with the sash assembly by a side-directed force. In some embodiments, as shown in
The window sash assembly, as used herein, includes the window sash. The window sash assembly also includes the carrier coupling portion and the carrier assembly contacting portion. In some embodiments, as shown in
The elimination of the need for a carrier channel in the jamb for the counterbalance assembly provides a number of advantages and benefits. The jamb itself, without a carrier channel proportioned for guidance of the carrier, can be made with less material and less precision, thereby reducing manufacturing costs. The carrier assembly can be made of a greater variety of materials, because it no longer needs to form sliding contact with carrier channel walls, and it no longer needs to be durable enough to withstand repeated contact with the carrier channel walls while moving up and down in the jamb, again reducing manufacturing costs. Without a carrier channel for the carrier in the jamb, the space in the jamb may be made larger for incorporation of a greater variety of balance designs as well.
A balance coupling portion of the carrier securely but reversibly couples the carrier to the balance. In some embodiments, the carrier has a hook to attach to a fastener or eyelet at the end of the rod of a spiral rod balance. A sash assembly coupling portion on the carrier securely but reversibly couples the carrier to the window sash assembly. The carrier assembly receives at least a portion of the load of the window sash assembly in the assembled window. In some embodiments, the carrier includes an elongated platform with an upstanding ledge to seat a corresponding feature on the sash assembly offset from the line of pull of the balance. The upward pull of the balance on the carrier in combination with the offset connection to the sash causes select surfaces, edges, or points of the carrier assembly to contact select surfaces, edges, or points of the sash assembly with sufficient force to maintain the contact during upward and downward movements of the window sash. In embodiments with a spiral balance, this engagement of the carrier assembly with the sash assembly preferably occurs with sufficient force and breadth of contact such that the torsional forces of the torsion spring do not alter the contact points between the carrier assembly and the sash assembly.
In some embodiments, the carrier is mounted to an encasement member. The encasement member may include at least one surface, edge, or point which contacts and is held against the sash assembly as a result of the side-directed force. The carrier may be mounted to the encasement member by fasteners, including, but not limited to, pins, rivets, screws, or bolts, or any other mounting means such as press-fitting.
In some embodiments, a carrier latch coupled to the carrier assembly secures the carrier to the jamb so that the sash can be lifted off the sash assembly coupling portion during removal of the window sash or placed on the sash assembly coupling portion during installation of the window sash. In some embodiments, the carrier latch is hingedly actuated. In other embodiments, the carrier latch is slidably actuated. In some embodiments, the carrier latch hooks into at least one slot or hole at one of a plurality of pre-determined locations on the jamb to hold the carrier in place. In some embodiments, the carrier latch reversibly engages the sash assembly to maintain the carrier latch in a non-interfering position in the assembled window. In other embodiments, the carrier latch is removed from the carrier assembly after the window sash has been installed.
Referring to the embodiment of
The carrier 20 is fixedly mounted in the carrier encasement element 30 by fasteners inserted through holes 32, 34 aligned with the middle fastener receptacle 28 and the lower fastener receptacle 29, respectively. The carrier encasement element 30 also includes an upper hole 36 to make the encasement element orientable with either side up. Two shoulder portions 38 having substantially flat vertical surfaces are formed on the carrier encasement element 30 on the side facing the sash 60 in the assembled window. The shoulder portions 38 engage the sash assembly as a result of the offset between the lifting and load forces so that the shoulders 38 establish the side-directed contact between the carrier and the sash and the carrier rides along with the sash as the sash moves up and down. In the assembled window, the fastener receptacles 28, 29 of the carrier 20 cooperate to press the carrier encasement element 30 against the sash assembly, thus clamping the carrier against the sash assembly so that the carrier no longer rubs up and down in a carrier channel.
Although two shoulder portions 38 are shown in
The carrier latch 40 includes a hook portion 42 at the upper end to hingedly engage a fastener extending through the hole 34 of the encasement member 30 and the lower fastener receptacle 29 of the carrier 20. A finger grip 44 is formed at the lower end of the carrier latch 40. The finger grip 44 aids in removing the carrier latch from the carrier assembly when the carrier latch is not in use and in attaching the carrier latch when the carrier latch is needed. Although the hook portion 42 in
Referring to
To install the sash 60 into the window frame, the balance 70 is first installed within a channel the jamb, traditionally by securing the upper end of the balance to the jamb by a screw, rivet, or other fastener. The carrier 20 is then coupled to the balance 70 and non-permanently held at a pre-determined location along the jamb by insertion of the protrusions 46 of the carrier latch 40 into at least one slot 48 in the wall 49 of the jamb as shown in
In embodiments of the present invention where the carrier latch 40 remains on the carrier assembly in the assembled window, it is desirable to maintain the carrier latch 40 in a position where it does not interfere with actuation of the window sash. In these embodiments, the sash assembly preferably includes a latch engagement element. The latch engagement element 56 may include a slot, as shown in
In the assembled window, the balance 70 applies an upward force 80 to one part of the carrier 20 and the sash bracket 50 applies a downward force 82 as a result of the weight of the sash assembly to another part of the carrier 20 offset from the upward force 80. This combination of forces results in a side-directed force driving the surfaces of the shoulder portions 38 of the carrier encasement element 30 to contact the carrier assembly contacting portion 58 of the sash bracket 50. The force is preferably sufficient to maintain non-sliding contact between the shoulder portions 38 and the carrier assembly contacting portion 58 as the window sash is moved up or down in the assembled window.
While the embodiments of the carrier assembly may be used with any balance, the following description focuses on spiral rod balances which exhibit a torsional force on the carrier. To install the carrier assembly 10, the end of the spiral rod 70 of a spiral rod balance is inserted through the slot 23 located within the hook segment 22 of the carrier 20. A fastener 12 located in proximity and secured to the end of the spiral rod 70 may be used to maintain engagement between the spiral rod 70 and the carrier 20.
As the spiral rod is extended further from the balance, the twisting force exhibited by the torsion spring increases. The side-directed force of the carrier assembly against the sash assembly is preferably strong enough to prevent the twisting force from the torsion spring from changing the contact points between the carrier assembly and the sash assembly.
Although the present invention has been described in terms of several preferred embodiments, alternative designs may be used within the spirit of the present invention. Various sash bracket designs may be used with carrier assemblies of the present invention. For example, three different sash bracket designs are shown in
There are several preferred ways in which the weight of the sash 60 may be supported by the carrier assembly 10.
Numerous different possible contacts between the balance assembly and the window sash assembly may be used to maintain the balance assembly in non-sliding contact with the window sash assembly. The contact preferably establishes an engagement plane defined by at least three non-linear points of contact between the carrier assembly and the sash assembly. In some embodiments, a line and a point form the engagement plane. In some embodiments, the carrier assembly has an area of contact between the slanted portion 90 and the sash bracket and at least one shoulder portion 38 and the sash bracket to prevent the carrier assembly from twisting. In an alternate embodiment, the shoulder portion 38 may be designed to form only a line of contact with the carrier assembly contacting portion 58 of the window sash assembly, as shown in
Alternative carrier assembly structures are shown schematically in
Although
In some embodiments, the carrier, the carrier latch, the fasteners, the spring element, and the sash bracket are made of a metal and the encasement member is made of plastic. In some embodiments, the metal is aluminum. In other embodiments the carrier and the encasement member are formed of plastic as a single integral piece.
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.
This is a continuation-in-part patent application of co-pending application Ser. No. 12/568,314, filed Sep. 28, 2009, entitled “SIDE LOAD CARRIER AND BALANCE SYSTEM FOR WINDOW SASHES”, which claims benefit of Provisional Application No. 61/101,694, filed Oct. 1, 2008, entitled “CARRIER AND BALANCE ATTACHMENT SYSTEM FOR SIDE LOADING SASH WINDOWS”. The benefit under 35 USC §119(e) of the U.S. provisional application is hereby claimed, and the aforementioned applications are hereby incorporated herein by reference.
Number | Date | Country | |
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61101694 | Oct 2008 | US |
Number | Date | Country | |
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Parent | 12568314 | Sep 2009 | US |
Child | 12907132 | US |