Abstract:
The carrier is securable to the end of a window balance, including, but not limited to, spiral rod, extension spring, and block and tackle balances. 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, until contact is made between the carrier assembly and the side of the sash. 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 a carrier channel in the jamb. The side-directed force preferably removes the carrier from any contact with a carrier channel, thereby eliminating friction from the carrier rubbing against the carrier channel and even eliminating the need for a carrier channel.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    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. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention pertains to the field of window sash balances. More particularly, the invention pertains to a carrier for attachment to a window balance. 
         [0004]    2. Description of Related Art 
         [0005]    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. 
         [0006]    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. 
       SUMMARY OF THE INVENTION 
       [0007]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  shows an isometric view of a carrier, an encasement member, and a carrier latch of a balance carrier assembly in an embodiment of the present invention. 
           [0009]      FIG. 2  shows the assembly of  FIG. 1  coupled to a window sash assembly. 
           [0010]      FIG. 3  shows an isometric view of the carrier of  FIG. 1 . 
           [0011]      FIG. 4  shows an isometric view of the carrier and the encasement member of  FIG. 1 . 
           [0012]      FIG. 5  shows an isometric view of the carrier latch of  FIG. 1 . 
           [0013]      FIG. 6  shows a cross sectional view of a carrier assembly on a wooden window frame assembly in an embodiment of the present invention. 
           [0014]      FIG. 7  shows a cross sectional view of a carrier assembly on an aluminum or fiberglass window frame assembly with the carrier latch secured in a hole of the jamb in an embodiment of the present invention. 
           [0015]      FIG. 8  shows the assembly of  FIG. 7 , where the carrier latch is secured on a ledge of the sash bracket. 
           [0016]      FIG. 9  shows a schematic cross-sectional view of the contact between a carrier assembly and a window sash assembly in one embodiment of the present invention. 
           [0017]      FIG. 10  shows a schematic cross-sectional view of the contact between a carrier assembly and a window sash assembly in another embodiment of the present invention. 
           [0018]      FIG. 11  shows a schematic cross-sectional view of the contact between a carrier assembly and a window sash assembly in yet another embodiment of the present invention. 
           [0019]      FIG. 12  shows a schematic isometric view of a carrier assembly, which supports the weight of a sash assembly by forming a horizontal contact line in an embodiment of the present invention. 
           [0020]      FIG. 13  shows a schematic isometric view of a carrier assembly, where the side-directed force forms a vertical contact line with a sash assembly in an embodiment of the present invention. 
           [0021]      FIG. 14  shows a schematic isometric cross-sectional view of a carrier assembly with an internal balance coupling structure in an embodiment of the present invention. 
           [0022]      FIG. 15  shows an isometric view of a balance, a carrier, and a sash bracket in an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    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. 
         [0024]    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  FIG. 15 , the carrier assembly includes only a carrier and the sash assembly contacting portion is part of the carrier. Although the carrier is shown as a single integral piece herein, the carrier may be formed of more than one piece. In some embodiments, as shown in  FIGS. 1-8 , the carrier assembly may also include an encasement member coupled to the carrier, where the sash assembly contacting portion is part of the encasement member. In some embodiments, the carrier assembly includes a carrier latch. 
         [0025]    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  FIGS. 2 ,  6 - 8 , and  15 , the window sash assembly includes a sash bracket attached to the sash, and the carrier coupling portion and the carrier assembly contacting portion are part of the sash bracket. In other embodiments, the carrier assembly contacting portion is part of the window sash itself or the window sash stile. In other embodiments, the carrier assembly contacting portion and carrier coupling portion are part of the window sash or window sash stile and there is no sash bracket. 
         [0026]    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. 
         [0027]    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. 
         [0028]    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. 
         [0029]    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. 
         [0030]    Referring to the embodiment of  FIGS. 1-5 , a carrier assembly  10  includes a carrier  20 , a carrier encasement element  30 , and a carrier latch  40 . The carrier  20  includes a hook segment  22  with a slot  23  at an upper end of the carrier  20  for coupling to the window balance and an elongated and substantially horizontal platform  24  with an upstanding ledge  26  at the lower end for non-permanently but securely engaging a complementary hook extension  52  of a corresponding sash bracket  50 , thereby sustaining the weight of the sash  60 . Although the carrier  20  is shown as having only a single slot  23  in  FIGS. 1-5 , the carrier  20  may have more than one slot  23  in the hook segment  22  within the spirit of the present invention. The carrier  20  also includes a leg  27  extending downward from a bottom surface of the carrier  20  to limit rotation of the carrier latch  40  toward the sash  60 . The bracket  50  includes an L-shaped brace  54  which is secured under a ledge located at the end of the rail  62  of the sash  60 . Two fastener receptacles, a middle fastener receptacle  28  and a lower fastener receptacle  29  located below the middle fastener receptacle  28 , are also formed in the carrier  20 . 
         [0031]    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. 
         [0032]    Although two shoulder portions  38  are shown in  FIGS. 1-5 , the encasement member  30  may have a single shoulder portion or more than two shoulder portions within the spirit of the present invention. When used with a spiral balance, the shoulder portion or portions engaging the sash assembly are wide enough and tall enough to ensure that the carrier assembly remains pressed against the sash assembly and that any torsional force on the carrier is unable to twist the carrier. Although the encasement member  30  is shown extending above the hook segment  22  of the carrier in  FIGS. 1-5 , the encasement member  30  may include only the lower holes  32 ,  34  with the top portion of the illustrated embodiments not present so that the hook segment  22  of the carrier  10  extends above the body of the encasement member  30 . 
         [0033]    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  FIG. 5  is shown as having a width extending the width of the carrier, the carrier latch may alternatively have one or more hook portions which may straddle or otherwise not overlap with the lower fastener receptacle  29  to engage different portions of the bottom fastener mounting carrier in the encasement member  30  such that the carrier latch  40  can be more securely mounted on the fastener with a greater freedom of rotation about the fastener. Alternatively, the carrier latch may be slidingly actuated. The carrier latch  40  also contains a pair of integrally formed protrusions  46  which are designed to securely fit into corresponding slots  48  located at one of a plurality of predetermined locations within the wall  49  of the jamb (see  FIG. 7 ). Upon securing the carrier assembly  10  at a specific location on the wall  49  of the jamb, the sash may be readily lifted away from the horizontal platform  24  of the carrier  20  to permit removal of the sash from the window frame. 
         [0034]    Referring to  FIGS. 6-8 , the carrier assembly  10  is preferably used in conjunction with a window balance  70 . The carrier  20  is attached to the extendable or free end of the window balance  70  by the hook segment  22  at the upper end and a fastener  12 .  FIGS. 6-8  also show the fasteners  14 ,  16  for mounting the carrier  20  in the carrier encasement element  30 .  FIG. 6  shows a wooden window frame assembly.  FIGS. 7 and 8  show an aluminum or fiberglass window frame assembly. 
         [0035]    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  FIG. 7 . Next, the sash  60  is manipulated so that the sash bracket  50 , already secured to the sash  60 , is seated on the horizontal platform  24 . The carrier latch  40  is then pivoted away from engagement with the slot  48  in the wall  49  of the jamb to engage a latch engagement element  56  of the sash bracket  50 , as shown in  FIGS. 6 and 8 . For removal of the sash  60 , upon securing the carrier assembly  10  at a specific location on the wall  49  of the jamb, the sash  60  may be readily lifted away from the horizontal platform  24  of the carrier  12  to permit removal of the sash from the window frame. 
         [0036]    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  FIG. 6  or it may be formed as a ledge, as shown in  FIGS. 7 and 8 . A spring element  18  on the back side of the carrier assembly  10 , a finger grip  44  on the carrier latch  40 , and a leg  27  of the carrier  20  may all assist with the engagement of the carrier latch  40  to the sash bracket  50 . The spring element  18  is preferably mounted in the encasement member  30  and biases the carrier latch  40  toward the latch engagement element  56 . A ramped portion  57  on the sash bracket  50  urges the carrier latch  40  into secure engagement with the latch engagement element  56 . The sash bracket  50  also includes a carrier assembly contacting portion  58 , which is substantially vertical and faces the carrier assembly  10  in the illustrated embodiments. In other embodiments, the carrier assembly contacting portion  58  is located on the window sash itself. In some embodiments, the shoulders  38  and the carrier assembly contacting portion  58  form a non-vertical area of contact. In some embodiments, the shoulders  38  and the carrier assembly contacting portion  58  form one or more points of contact, one or more lines of contact, or one or more areas of contact. 
         [0037]    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. 
         [0038]    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 . 
         [0039]    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. 
         [0040]    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  FIGS. 2 ,  6 , and  7 . Alternative sash brackets may be used for sashes made from different materials. Any sash bracket which securely but non-permanently couples the sash to the carrier balance may be used within the spirit of the present invention. Alternatively, the window sash may be formed with a carrier coupling portion so that no sash bracket is needed. 
         [0041]    There are several preferred ways in which the weight of the sash  60  may be supported by the carrier assembly  10 .  FIG. 9  shows the weight being supported by contact with a slanted portion  90  and an end portion  92  of the carrier.  FIG. 10  shows the weight being supported by contact with a slanted portion  90  and the platform  24  of the carrier.  FIG. 11  shows the weight being supported by contact with a slanted portion  90 , an end portion  92 , and the platform  24  of the carrier.  FIG. 12  shows a carrier assembly where the end portion  92  is designed to form a line of contact with the sash bracket to support a portion of the weight of the sash. The carrier assembly of  FIG. 12  also includes a slanted portion  90  for supporting a portion of the weight of the sash. 
         [0042]    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  FIG. 13 . The combined contact of the slanted portion  90  and the shoulder portion  38  in this embodiment with the sash bracket is sufficient to maintain non-sliding contact and to prevent twisting of the carrier assembly. 
         [0043]    Alternative carrier assembly structures are shown schematically in  FIGS. 13 and 14 . The upper portion of the carrier has a cylindrical shape in  FIG. 13  with a slot  23  in the top and flanking portions  22  for non-permanently coupling the balance to the carrier. The balance is coupled to the carrier assembly in an internal space of the carrier in  FIG. 14 . The end of the balance is maintained in a slot  23  in the carrier assembly by flanking portions  22  of the carrier assembly of  FIG. 14 . Although several means of coupling a balance to a carrier have been described herein, any method or means of securely but non-permanently coupling the balance to the carrier may be used within the spirit of the present invention. 
         [0044]    Although  FIGS. 1-14  show carrier assemblies where the balance coupling portion is located vertically higher than the sash assembly coupling portion in the assembled counterbalance system, the balance coupling portion may alternatively be located in vertical alignment with the sash assembly coupling portion or vertically lower than the sash assembly coupling portion as shown in  FIG. 15 . The carrier  20  includes a hook segment  22  with a slot  23  at a lower portion of the carrier  20 . The window balance  70  is inserted into the slot  23  and reversibly coupled to the hook segment by a pin or knob  12  on the window balance  70 . An upstanding ledge  26  in a middle section of the carrier  20  non-permanently but securely engages a complementary hook extension  52  of a corresponding sash bracket  50  attached to a window sash. The carrier  20  includes an integral shoulder portion  38 , which applies a side load to the carrier assembly contacting portion  58  of the sash assembly as a result of the offset between the lifting and load forces so that the shoulder  38  establishes the contact between the carrier and the sash, and the carrier rides along with the sash as the sash moves up and down. In the embodiment illustrated in  FIG. 15 , the shoulder portion  38  is part of the carrier  20 , and no encasement member is needed. 
         [0045]    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. 
         [0046]    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.